chore: Table grid navigation (no integration)

[pan-kot]

Description

Added new navigation mechanism for table grids. For now the change is tested on a custom table and only minimal changes to the official table component are made so that everything can be tested and merged incrementally.

Eventually the new navigation will replace the current one for editable tables (use-table-focus-navigation.ts) and for selection column (useSelection.ts:useFocusMove) and will be offered for all tables with a dedicated API.

How has this been tested?

New unit and integration tests to cover the change. Screenshot tests.

The behaviour can be manually tested in the new test page.

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

Patch coverage: 99.58% and project coverage change: +0.14% 🎉

Comparison is base (2ca759e) 93.56% compared to head (7aa0555) 93.70%.
Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1389      +/-   ##
==========================================
+ Coverage   93.56%   93.70%   +0.14%     
==========================================
  Files         633      636       +3     
  Lines       16901    17161     +260     
  Branches     5581     5658      +77     
==========================================
+ Hits        15813    16081     +268     
+ Misses       1016     1008       -8     
  Partials       72       72              

Files Changed	Coverage Δ
src/table/header-cell/index.tsx	92.85% <ø> (ø)
src/table/table-role/use-grid-navigation.ts	99.22% <99.22%> (ø)
src/table/body-cell/td-element.tsx	91.30% <100.00%> (ø)
src/table/internal.tsx	99.25% <100.00%> (+0.71%)	⬆️
src/table/table-role/table-role-helper.ts	100.00% <100.00%> (ø)
src/table/table-role/utils.ts	100.00% <100.00%> (ø)
src/table/thead.tsx	95.45% <100.00%> (+0.10%)	⬆️

... and 12 files with indirect coverage changes

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[gethinwebster]

General comment on this functionality: can we document somewhere accessible to customers (perhaps on the website?) the expected behavior/interactions? From what I remember from the last call, there were quite a few edge cases/tradeoffs related to interactive elements in cells, and the standards/guidelines aren't entirely clear, so it would be good to write down how and why the component/feature behaves.

(This has been a regular ask from customers for existing functionality, and for something complex like this I think it's even more valuable)

[pan-kot]

General comment on this functionality: can we document somewhere accessible to customers (perhaps on the website?) the expected behavior/interactions? From what I remember from the last call, there were quite a few edge cases/tradeoffs related to interactive elements in cells, and the standards/guidelines aren't entirely clear, so it would be good to write down how and why the component/feature behaves.

(This has been a regular ask from customers for existing functionality, and for something complex like this I think it's even more valuable)

Sure, that makes total sense - I will add the docs.

[gethinwebster]

Should this be a feat? As far as I see there's no public changes so far, so we probably don't e.g. want this in the changelog

[pan-kot]

@gethinwebster, I added the doc explaining the current behaviour. I am expecting certain changes to come as result of further discussions, bug bashes, integration with the table, and the API proposal - I will make sure to reflect those changes in the doc.

[gethinwebster]

Looks great!