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);
```
On android `suspend/resume` was not doing what was expected.
In particular it was called while showing dialogs. This adds new `background` and `foreground` events which will fire expectedly and consistently for ios and android.
Cleanup type symbol usage by consolidating to manage in one spot. This makes them easier to use as well by providing a single rollup of all the common type symbol's used throughout core.
