refactor: improved core barrel exports and Application class (#10286)

BREAKING CHANGES:

`Application.orientation` is no longer a function.

Migration: Remove `()` from the `Application.orientation()` call:
```diff
import { Application } from "@nativescript/core";

-console.log(Application.orientation());
+console.log(Application.orientation);
```


`Application.systemAppearance` is no longer a function.

Migration: Remove `()` from the `Application.systemAppearance()` call:
```diff
import { Application } from "@nativescript/core";

-console.log(Application.systemAppearance());
+console.log(Application.systemAppearance);
```

packages/core/application/application-interfaces.ts

@@ -1,6 +1,6 @@
-// Types
-import { EventData } from '../data/observable';
-import { View } from '../ui/core/view';
+import type { ApplicationCommon } from './application-common';
+import type { EventData, Observable } from '../data/observable';
+import type { View } from '../ui/core/view';
 
 /**
  * An extended JavaScript Error which will have the nativeError property initialized in case the error is caused by executing platform-specific code.
@@ -12,98 +12,191 @@ export interface NativeScriptError extends Error {
 	nativeError: any;
 }
 
-export interface ApplicationEventData extends EventData {
+/**
+ * Event data containing information for the application events.
+ */
+export interface ApplicationEventData {
 	/**
-	 * UIApplication or undefined, unless otherwise specified. Prefer explicit
-	 * properties where possible.
+	 * The name of the event.
 	 */
-	ios?: any;
+	eventName: string;
+
 	/**
-	 * androidx.appcompat.app.AppCompatActivity or undefined, unless otherwise
-	 * specified. Prefer explicit properties where possible.
+	 * Gets the native iOS event arguments. Valid only when running on iOS.
 	 */
-	android?: any;
+	ios?: any; // iOSApplication;
+
 	/**
-	 * Careful with this messy type. A significant refactor is needed to make it
-	 * strictly extend EventData['object'], which is an Observable. It's used in
-	 * various ways:
-	 * - By font-scale: the Application module, typeof import('.')
-	 * - Within index.android.ts: AndroidApplication
-	 * - Within index.ios.ts: iOSApplication
+	 * Gets the native Android event arguments. Valid only when running on Android.
 	 */
-	object: any;
+	android?: any; // AndroidApplication;
+
+	/**
+	 * The instance that has raised the event.
+	 */
+	object: ApplicationCommon | Observable;
 }
 
-export interface LaunchEventData extends ApplicationEventData {
+/**
+ * Event data containing information for launch event.
+ */
+export interface LaunchEventData extends EventData {
 	/**
-	 * The value stored into didFinishLaunchingWithOptions notification's
-	 * userInfo under 'UIApplicationLaunchOptionsLocalNotificationKey';
-	 * otherwise, null.
+	 * The root view for this Window on iOS or Activity for Android.
+	 * If not set a new Frame will be created as a root view in order to maintain backwards compatibility.
+	 * If explicitly set to null, there will be no root view.
 	 */
-	ios: unknown;
 	root?: View | null;
+
 	savedInstanceState?: any /* android.os.Bundle */;
+
+	android?: android.content.Intent;
+
+	ios?: any /* UIApplicationLaunchOptions */;
 }
 
+/**
+ * Event data containing information for orientation changed event.
+ */
 export interface OrientationChangedEventData extends ApplicationEventData {
-	android: any /* globalAndroid.app.Application */;
+	/**
+	 * New orientation value.
+	 */
 	newValue: 'portrait' | 'landscape' | 'unknown';
 }
 
+/**
+ * Event data containing information for system appearance changed event.
+ */
 export interface SystemAppearanceChangedEventData extends ApplicationEventData {
-	android: any /* globalAndroid.app.Application */;
+	/**
+	 * New system appearance value.
+	 */
 	newValue: 'light' | 'dark';
 }
 
+/**
+ * Event data containing information for font scale changed event.
+ */
+export interface FontScaleChangedEventData extends ApplicationEventData {
+	/**
+	 * New font scale value.
+	 */
+	newValue: number;
+}
+
+/**
+ * Event data containing information about unhandled application errors.
+ */
 export interface UnhandledErrorEventData extends ApplicationEventData {
 	ios?: NativeScriptError;
 	android?: NativeScriptError;
 	error: NativeScriptError;
 }
 
+/**
+ * Event data containing information about discarded application errors.
+ */
 export interface DiscardedErrorEventData extends ApplicationEventData {
 	error: NativeScriptError;
 }
 
+/**
+ * Event data containing information about application css change.
+ */
 export interface CssChangedEventData extends ApplicationEventData {
 	cssFile?: string;
 	cssText?: string;
 }
 
-export interface AndroidActivityEventData extends ApplicationEventData {
-	activity: any /* androidx.appcompat.app.AppCompatActivity */;
-	object: any /* AndroidApplication */;
-}
+/**
+ * Data for the Android activity events.
+ */
+export interface AndroidActivityEventData {
+	/**
+	 * The activity.
+	 */
+	activity: androidx.appcompat.app.AppCompatActivity;
 
-export interface AndroidActivityBundleEventData extends AndroidActivityEventData {
-	bundle: any /* android.os.Bundle */;
-}
+	/**
+	 * The name of the event.
+	 */
+	eventName: string;
 
-export interface AndroidActivityRequestPermissionsEventData extends AndroidActivityEventData {
-	requestCode: number;
-	permissions: Array<string>;
-	grantResults: Array<number>;
-}
-
-export interface AndroidActivityResultEventData extends AndroidActivityEventData {
-	requestCode: number;
-	resultCode: number;
-	intent: any /* android.content.Intent */;
-}
-
-export interface AndroidActivityNewIntentEventData extends AndroidActivityEventData {
-	intent: any /* android.content.Intent */;
-}
-
-export interface AndroidActivityBackPressedEventData extends AndroidActivityEventData {
-	cancel: boolean;
+	/**
+	 * The instance that has raised the event.
+	 */
+	object: any;
 }
 
 /**
- * @deprecated
+ * Data for the Android activity events with bundle.
  */
-export interface RootViewControllerImpl {
-	contentController: any;
+export interface AndroidActivityBundleEventData extends AndroidActivityEventData {
+	/**
+	 * The bundle.
+	 */
+	bundle: android.os.Bundle;
+}
+
+/**
+ * Data for the Android activity onRequestPermissions callback
+ */
+export interface AndroidActivityRequestPermissionsEventData extends AndroidActivityEventData {
+	/**
+	 * The request code.
+	 */
+	requestCode: number;
+
+	/**
+	 * The Permissions.
+	 */
+	permissions: Array<string>;
+
+	/**
+	 * The Granted.
+	 */
+	grantResults: Array<number>;
+}
+
+/**
+ * Data for the Android activity result event.
+ */
+export interface AndroidActivityResultEventData extends AndroidActivityEventData {
+	/**
+	 * The request code.
+	 */
+	requestCode: number;
+
+	/**
+	 * The result code.
+	 */
+	resultCode: number;
+
+	/**
+	 * The intent.
+	 */
+	intent: android.content.Intent;
+}
+
+/**
+ * Data for the Android activity newIntent event.
+ */
+export interface AndroidActivityNewIntentEventData extends AndroidActivityEventData {
+	/**
+	 * The intent.
+	 */
+	intent: any /* android.content.Intent */;
+}
+
+/**
+ * Data for the Android activity back pressed event.
+ */
+export interface AndroidActivityBackPressedEventData extends AndroidActivityEventData {
+	/**
+	 * In the event handler, set this value to true if you want to cancel the back navigation and do something else instead.
+	 */
+	cancel: boolean;
 }
 
 export interface LoadAppCSSEventData extends ApplicationEventData {