[stable8] feat: add NcFormBoxCopyButton

[backportbot]

Backport of #7787

Warning, This backport's changes differ from the original and might be incomplete ⚠️

Todo

• Review and resolve any conflicts
• Amend HEAD commit to remove the line stating to skip CI

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[codecov]

Codecov Report

❌ Patch coverage is 40.54054% with 22 lines in your changes missing coverage. Please review.
✅ Project coverage is 44.69%. Comparing base (3a477e1) to head (13e6950).
⚠️ Report is 2 commits behind head on stable8.

Files with missing lines	Patch %	Lines
...onents/NcFormBoxCopyButton/NcFormBoxCopyButton.vue	56.00%	11 Missing ⚠️
src/components/NcFormBoxCopyButton/useCopy.ts	8.33%	11 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           stable8    #7793      +/-   ##
===========================================
- Coverage    44.71%   44.69%   -0.03%     
===========================================
  Files          185      187       +2     
  Lines         4607     4652      +45     
  Branches      1145     1151       +6     
===========================================
+ Hits          2060     2079      +19     
- Misses        2454     2480      +26     
  Partials        93       93              

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