Table: Add design tokens and update default header background

[brentswisher]

This change: (check at least one)

• [X] Adds a new feature
• [ ] Fixes a bug
• [ ] Improves maintainability
• [ ] Improves documentation
• [ ] Is a release activity

Is this a breaking change? (check one)

• [ ] Yes
• [X] No

Is the: (complete all)

• [X] Title of this pull request clear, concise, and indicative of the issue number it addresses, if any?
• [X] Test suite(s) passing?
• [X] Code coverage maximal?
• [X] Changeset added?
• [X] Component status page up to date?

What does this change address? Close #806

How does this change work? Adds new component level tokens for that table and updates the header to have a light gray background by default.

Additional context New Default Header:

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: c7c79ea1ec112990bab6215297f6a6e1cdf7b821

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

| Name | Type | | -------------- | ----- | | @ithaka/pharos | Minor |

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions[bot]]

size-limit report 📦

Path	Size
packages/pharos/lib/index.js	65.92 KB (+0.07% 🔺)