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/select.tsx

@@ -455,6 +455,7 @@ export class Select implements ComponentInterface {
       'aria-haspopup': 'dialog',
       'aria-labelledby': labelId,
       class: {
+        [`${this.mode}`]: true,
         'in-item': hostContext('ion-item', this.el),
         'select-disabled': this.disabled,
       }