feat: Table column groups API II

[NathanZlion]

Description

Related links, issue #, if available: n/a

How has this been tested?

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 is 62.78447% with 278 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.50%. Comparing base (470a8cb) to head (14fef4f).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/table/header-cell/group-header-cell.tsx	38.12%	106 Missing and 6 partials ⚠️
src/table/use-column-widths.tsx	36.14%	46 Missing and 7 partials ⚠️
...rc/collection-preferences/content-display/utils.ts	30.43%	31 Missing and 1 partial ⚠️
src/table/column-grouping-utils.ts	86.45%	21 Missing ⚠️
...llection-preferences/content-display-preference.ts	16.66%	16 Missing and 4 partials ⚠️
...c/collection-preferences/content-display/index.tsx	46.66%	16 Missing ⚠️
src/table/thead.tsx	84.44%	14 Missing ⚠️
src/table/table-role/grid-navigation.tsx	84.61%	3 Missing and 1 partial ⚠️
src/collection-preferences/index.tsx	81.81%	2 Missing ⚠️
src/table/table-role/utils.ts	93.33%	2 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4347      +/-   ##
==========================================
- Coverage   97.45%   96.50%   -0.95%     
==========================================
  Files         909      912       +3     
  Lines       26637    27326     +689     
  Branches     9615     9874     +259     
==========================================
+ Hits        25958    26370     +412     
- Misses        636      894     +258     
- Partials       43       62      +19     

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