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/toast/toast.tsx

@@ -226,6 +226,8 @@ export class Toast implements ComponentInterface, OverlayInterface {
         zIndex: 60000 + this.overlayIndex,
       },
       class: {
+        [`${this.mode}`]: true,
+
         ...createColorClasses(this.color),
         ...getClassMap(this.cssClass),
         'toast-translucent': this.translucent