Improve theming support

[myvuuu]

Only 30-40% of Canvas components support theming (and only for colorful items), we need to provide theming support for:

• TBD

This is not dependent on rolling out the new color system, but would be ideal to start after IE11 retires for more CSS functionality.

Open Questions:

• Do we want to support dark mode?

• Do we want to wait until after the new color system rolls out?

• How holistic should theming be?

** Waiting for more confirmation about what needs to be themed and the new color system model.

[mannycarrera4]

I'm gonna close this as this is part of the work of us updating our components to use our new tokens.