Add theme support for table component

[britneywwc]

Done

• Update table colour variables to inherit CSS variables

Fixes WD-8976

QA

• Open demo
• Check the table examples in the docs, change the parent container to is-dark and check if styles update accordingly

Check if PR is ready for release

If this PR contains Vanilla SCSS code changes, it should contain the following changes to make sure it's ready for the release:

• PR should have one of the following labels to automatically categorise it in release notes:
  • Feature 🎁, Breaking Change 💣, Bug 🐛, Documentation 📝, Maintenance 🔨.
• Vanilla version in package.json should be updated relative to the most recent release, following semver convention:
  • if CSS class names are not changed it can be bugfix release (x.x.X)
  • if CSS class names are changed/added/removed it should be minor version (x.X.0)
  • see the wiki for more details
• Any changes to component class names (new patterns, variants, removed or added features) should be listed on the what's new page.

Screenshots

[if relevant, include a screenshot or screen capture]

[webteam-app]

Demo starting at https://vanilla-framework-5000.demos.haus

[bartaz]

Please add dark examples for mobile card and sortable tables.

[bartaz]

Great, thanks for that!