chore: Table grid nav updates

[pan-kot]

Description

Made changes to the table grid navigation based on an integration attempt (see #1480).

The main changes are:

• Moving from focused cell to a cell containing one focusable element focuses the element and not the cell itself.
• When focus is inside a widget cell the Tab/Shift+Tab can be used to move focus back to the table.
• The navigation now works when the first data row index is other than 1.

How has this been tested?

• New unit tests
• Updated existing integ test

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: 95.23% and project coverage change: -0.02% ⚠️

Comparison is base (99e8bbf) 93.78% compared to head (0f6ea43) 93.77%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1478      +/-   ##
==========================================
- Coverage   93.78%   93.77%   -0.02%     
==========================================
  Files         639      639              
  Lines       17228    17257      +29     
  Branches     5665     5677      +12     
==========================================
+ Hits        16158    16183      +25     
- Misses        997     1001       +4     
  Partials       73       73              

Files Changed	Coverage Δ
src/table/table-role/table-role-helper.ts	96.07% <83.33%> (-3.93%)	⬇️
src/table/table-role/utils.ts	98.14% <97.77%> (-1.86%)	⬇️
src/table/internal.tsx	99.25% <100.00%> (ø)
src/table/table-role/use-grid-navigation.ts	99.23% <100.00%> (+<0.01%)	⬆️

... and 1 file with indirect coverage changes

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