feat: adds a renderSlot to NavTabList after content

[dsmmcken]

To adopt NavTabList in enterprise, we need to be able to attach a popper to a navtab. This PR creates a slot that goes after the title, that takes a render function, passing in the tab.

Enterprise has a diverged from Core and is lacking bug fixes, so I would like to get NavTabList de-duplicated and used in Enterprise.

Testing:
Tested by manually creating popper in styleguide, worked as expected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 45.11%. Comparing base (590def3) to head (1e3c039).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2565      +/-   ##
==========================================
- Coverage   45.16%   45.11%   -0.06%     
==========================================
  Files         769      769              
  Lines       43463    43463              
  Branches    11170    10989     -181     
==========================================
- Hits        19632    19608      -24     
- Misses      23815    23839      +24     
  Partials       16       16              

Flag	Coverage Δ
unit	45.11% <ø> (-0.06%)	⬇️

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[Copilot]

Pull Request Overview

This PR adds a renderTabSlot prop to the NavTabList component, allowing consumers to render custom content after each tab's title. This provides flexibility for adding tab-specific UI elements like badges or indicators.

• Adds optional renderTabSlot prop to NavTabList and NavTab components
• Renders slot content after tab title and before close button
• Includes test coverage for the new functionality

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
packages/components/src/navigation/NavTabList.tsx	Adds renderTabSlot prop definition with JSDoc and threads it through to NavTab
packages/components/src/navigation/NavTab.tsx	Adds renderTabSlot prop and renders slot content after tab title
packages/components/src/navigation/NavTabList.test.tsx	New test file with coverage for renderTabSlot functionality

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[dsmmcken]

@copilot fix all the comments

[Copilot]

@dsmmcken I've opened a new pull request, #2573, to work on those changes. Once the pull request is ready, I'll request review from you.