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/textarea/textarea.tsx

@@ -266,7 +266,10 @@ export class Textarea implements ComponentInterface {
   hostData() {
     return {
       'aria-disabled': this.disabled ? 'true' : null,
-      class: createColorClasses(this.color)
+      class: {
+        ...createColorClasses(this.color),
+        [`${this.mode}`]: true,
+      }
     };
   }