fix(components): include mode classes on components for use in shadow (#17838)

- removes mode-less component classes from the internal CSS, use element instead
- adds mode specific classes `md` or `ios` for styling inside of shadow components
- adds e2e test that verifies mode classes exist on all ionic components, plus checks for specific classes that the components need for internal styling

fixes #17608

core/src/components/select-option/select-option.tsx

@@ -1,11 +1,14 @@
 import { Component, ComponentInterface, Element, Event, EventEmitter, Prop } from '@stencil/core';
 
+import { Mode } from '../../interface';
+
 @Component({
   tag: 'ion-select-option',
   shadow: true,
   styleUrl: 'select-option.scss'
 })
 export class SelectOption implements ComponentInterface {
+  mode!: Mode;
 
   private inputId = `ion-selopt-${selectOptionIds++}`;
 
@@ -55,7 +58,10 @@ export class SelectOption implements ComponentInterface {
   hostData() {
     return {
       'role': 'option',
-      'id': this.inputId
+      'id': this.inputId,
+      class: {
+        [`${this.mode}`]: true,
+      }
     };
   }
 }