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-popover/select-popover.tsx

@@ -34,6 +34,14 @@ export class SelectPopover implements ComponentInterface {
     }
   }
 
+  hostData() {
+    return {
+      class: {
+        [`${this.mode}`]: true,
+      }
+    };
+  }
+
   render() {
     return (
       <ion-list>