chore(pageheader): organize stories in storybook and add documentation in overview

[annawen1]

Closes #19493

This PR exposes the PageHeader stories as experimental under the "Patterns" section of Storybook and adds technical documentation

Changelog

New

• added some controls to the Default story

Changed

• change the pageActions prop name in PageHeader.ContentPageActions to actions to make it less repetitive
• use justify-content: flex-end as justify-content: end has been deprecated

Removed

• remove unused components and imports
• remove the Content, BreadcrumbBar, and TabBar stories in favor of variations of the PageHeader with some/all of zones together

Testing / Reviewing

Review the stories and let me know if I should remove/add any stories or controls

Review the documentation in the Overview section.

PR Checklist

As the author of this PR, before marking ready for review, confirm you:

• Reviewed every line of the diff
• Updated documentation and storybook examples
• [ ] Wrote passing tests that cover this change
• [ ] Addressed any impact on accessibility (a11y)
• [ ] Tested for cross-browser consistency
• Validated that this code is ready for review and status checks should pass

More details can be found in the pull request guide

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.57%. Comparing base (f0c53fb) to head (d7074b3).
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #19520      +/-   ##
==========================================
+ Coverage   84.48%   84.57%   +0.09%     
==========================================
  Files         373      373              
  Lines       14645    14675      +30     
  Branches     4840     4804      -36     
==========================================
+ Hits        12373    12412      +39     
+ Misses       2125     2116       -9     
  Partials      147      147              

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[ariellalgilmore]

LGTM!

[kingtraceyj]

looks good! 💥

[riddhybansal]

Hey In overview page I can see undefined here in component api