feat: Add new TableHeaderRow

[kurtdoherty]

Context

• We have table atoms in @reapit/elements/lab/table, but these don't facilitate the level of nuance required by the DS. For example:
  • They are pinned to semantic table elements like td, tr and so on, but we may need the flexibility of using them in a div-based DOM structure instead.
  • They do not provide any solution for the primary row action (which is meant to appear like the row itself is interactive).
  • They do not provide any solution for rendering row header cells.
  • They require column widths to be defined at the cell-level of the table rather than once at the table-level.
• We want to enhance the capability of our table atoms when implementing "official" core versions of them (i.e. the table atoms that will be available via @reapit/elements/core/table.
• The first chunk of this work focused on atoms involved in the table's body and was completed over a number of PRs: feat: Add new TableRowPrimaryAction #715, feat: Add new TableCellPrimaryData #716, feat: Add new TableCellDoubleLineLayout #717, feat: Add new TableBodyCell #718, feat: Add new TableBodyRow #719, feat: Add new TableBody #720 and feat: Add new TableRowMoreActions #721.
• The next chunk of work will be focused on the atoms involved in the table's head:
  • Part 1: feat: Add new TableCellSortButton #725
  • Part 2: feat: Add new TableHeaderCell #726
  • Part 3: Header row (this PR)
  • Part 4: Table head

This PR

• Adds TableHeaderRow.

[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 79c9d1e1	✅ 100.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (79c9d1e)	Report Missing	Report Missing	Report Missing
Head commit (23ee088)	8534	7895	92.51%

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 (#727)	9	9	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. ↩