fix(select, combo): update focus styles for toggle and clear buttons

[desig9stein]

Related to: #446
Depends on this theming package: IgniteUI/igniteui-theming#459

In addition to the select fix, there is a small style enhancement for the combo toggle and select styles on focus

Additional information (check all that apply):

• Bug fix
• New functionality
• Documentation
• Demos
• CI/CD

Checklist:

• All relevant tags have been applied to this PR
• This PR includes unit tests covering all the new code (test guidelines)
• This PR includes API docs for newly added methods/properties (api docs guidelines)
• This PR includes feature/README.MD updates for the feature docs
• This PR includes general feature table updates in the root README.MD
• This PR includes CHANGELOG.MD updates for newly added functionality
• This PR contains breaking changes
• This PR includes ng update migrations for the breaking changes (migrations guidelines)
• This PR includes behavioral changes and the feature specification has been updated with them

[adrianptrv]

I noticed that in the Combo component, when using the material border style, focusing on the combo clear element applies a light background to the clear button and a dark background to the toggle button. Then, when you press Tab again and go on the toggle button, it receives a light background.

The coloring of both elements matches what you see when using the Material box variant.

IgniteuiDevDemos.6.mp4