fix(link): fix accessibility by inlining link functionality into Shadow DOM

[TomMenga]

This PR Closes #2514, #2604, #2376, #2496

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BEGIN_COMMIT_OVERRIDE
fix(sbb-link): fix accessibility by inlining link functionality into Shadow DOM

BREAKING CHANGE: Due to screen reader limitations, we had to move the link role inside the Shadow DOM. Therefore, for the following components, replace the [aria-label] usages with [accessibility-label] attribute or accessibilityLabel property:

• sbb-breadcrumb
• sbb-button-link, sbb-secondary-button-link, sbb-tertiary-button-link, sbb-transparent-button-link
• sbb-card-link
• sbb-header-link
• sbb-link, sbb-block-link
• sbb-menu-link
• sbb-navigation-link
• sbb-teaser, sbb-teaser-hero, sbb-teaser-paid

END_COMMIT_OVERRIDE

[DavideMininni-Fincons]

Very good 👍
General comment: the change from aria-label to accessibility-label must be added in the readme of all the components influenced by this changes.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 95.34884% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 93.20%. Comparing base (e6397df) to head (3bb30db).
Report is 75 commits behind head on main.

Files	Patch %	Lines
src/components/menu/menu/menu.ts	0.00%	4 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2571      +/-   ##
==========================================
+ Coverage   93.18%   93.20%   +0.01%     
==========================================
  Files         316      316              
  Lines       25389    25344      -45     
  Branches     2063     2069       +6     
==========================================
- Hits        23660    23621      -39     
+ Misses       1696     1690       -6     
  Partials       33       33              

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[jeripeierSBB]

Thanks for deep diving here! A few fixes needed and maybe more manual testing as I found some not working or wrongly displayed focus outlines?

[jeripeierSBB]

LGTM, thanks for all the patience! :-). Please wait with merge, as we maybe have to release another non breaking fix.

[DavideMininni-Fincons]

LGTM, thanks