chore: refactor EmptyData

[kurtdoherty]

This PR

• Refactors EmptyData to align with latest patterns/conventions
• Adds height prop to all a fixed height to be specified.
• Removes EmptyData.SecondaryDesciption in favour of new secondaryText prop on EmptyData.Description
• Updates EmptyData.Description to render the title as a h3 element.
• Adds new EmptyData.Action for anchor-based actions. It's based on Button.
• Updates EmptyData.ActionButton to be best on Button too.
• Scouts an update to our design tokens to match latest changes in Figma.

[rpt-uk-github]

🎉 Snyk checks have passed. No issues have been found so far.

✅ security/snyk check is complete. No issues have been found. (View Details)

✅ license/snyk check is complete. No issues have been found. (View Details)

✅ code/snyk check is complete. No issues have been found. (View Details)

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
Report missing for 502e00a1	✅ 100.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (502e00a)	Report Missing	Report Missing	Report Missing
Head commit (cfaf1ec)	8248	7611	92.28%

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#697)	34	34	100.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences

Footnotes

1. Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct. ↩