fix(tabs): replace igx-icon with igc-icon in WC demo + fix theme parameters

[adrianptrv]

Related to: #1915
Requires this theming PR: 495

• Replaced igx-icon with igc-icon in the WC Tabs demo.
• Fixed the $border-radius theme parameter so it works correctly.
• Updated $item-background to apply only to Tab items instead of both Tab items and the Tab Header.
• Set up the three new theme parameters - $item-active-hover-background $item-active-hover-color $item-active-hover-icon-color

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

[desig9stein]

THEME: INDIGO
It looks like item-active-background is not used anywhere in the Indigo theme. Its current value also seems incorrect: when I apply it in the expected place, it renders as transparent. I believe it should use the same color as the item-hover-background, since that’s what is currently used in that state.

[adrianptrv]

THEME: INDIGO It looks like item-active-background is not used anywhere in the Indigo theme. Its current value also seems incorrect: when I apply it in the expected place, it renders as transparent. I believe it should use the same color as the item-hover-background, since that’s what is currently used in that state.

I have added and set up three new parameters for the active tab - $item-active-hover-background $item-active-hover-color $item-active-hover-icon-color
The changes can now be tested again using this theming PR: 495

[desig9stein]

@adrianptrv, the active background is still not working. I should be able to see the active background on the active tab in the idle state and the active hover background when I hover the active tab.