refactor(components): update to use shadow DOM and work with css variables

- updates components to use shadow DOM or scoped if they require css variables
- moves global styles to an external stylesheet that needs to be imported
- adds support for additional colors and removes the Sass loops to generate colors for each component
- several property renames, bug fixes, and test updates

Co-authored-by: Manu Mtz.-Almeida <manu.mtza@gmail.com>
Co-authored-by: Adam Bradley <adambradley25@gmail.com>
Co-authored-by: Cam Wiegert <cam@camwiegert.com>

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

@@ -2,10 +2,7 @@ import { Component, Element, Event, EventEmitter, Prop } from '@stencil/core';
 
 
 @Component({
-  tag: 'ion-select-option',
-  host: {
-    theme: 'select-option'
-  }
+  tag: 'ion-select-option'
 })
 export class SelectOption {