feat(tabs): update theme according to new Indigo design

[SisIvanova]

Related to IgniteUI/igniteui-theming/issues/327

Hand-off: https://www.figma.com/design/rIwpaKXD3IgFtOohUV9Zi4/Tabs-in-Indigo-Handoff?node-id=1-4844&node-type=frame&t=tpZ8mIYbO20WBYY6-0

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

[andiesm813]

@SisIvanova i'm sure i must have something different, because i see some of the css properties incorrect, and i know we discussed some of the colors, so maybe there's something wrong on my end.....

Regardless, i will list the css variables that are expected:

Light Theme

--item-text-color: --ig-gray-800
--item-hover-background: --ig-gray-900 5%
--item-disabled-color: --ig-gray-900 20%

--item-icon-color: --ig-gray-600
--item-active-icon-color: --ig-gray-700
--item-hover-icon-color: --ig-gray-700
--item-disabled-icon-color: --ig-gray-900 20%

--button-color: --ig-gray-600
--button-hover-background: --ig-gray-900 5%
--button-hover-color: --ig-gray-700
--button-disabled-color: --ig-gray-900 20%

--tab-ripple-color: transparent
--button-ripple-color: transparent

--border-color: --ig-gray-900 15%
--border-color--hover: transparent
--border-radius: 0

Dark Theme

--item-text-color: white 80%
--item-hover-background: white 10%
--item-disabled-color: white 20%

--item-icon-color: white 60%
--item-active-icon-color: white 80%
--item-hover-icon-color: white 80%
--item-disabled-icon-color: white 20%

--button-color: white 80%
--button-hover-background: white 10%
--button-hover-color: white
--button-disabled-color: white 20%

--tab-ripple-color: transparent
--button-ripple-color: transparent

--border-color: white 15%
--border-color--hover: transparent
--border-radius: 0