[stable8] fix(NcFormBox): add NcButton to supported components

[backportbot]

Backport of #7886

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

Todo

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

---

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

[Antreesy]

Rewrote first commit only (Composition API > Options API)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 46.54%. Comparing base (58e08ac) to head (d9e2827).
⚠️ Report is 4 commits behind head on stable8.

Additional details and impacted files

@@             Coverage Diff             @@
##           stable8    #7898      +/-   ##
===========================================
+ Coverage    46.52%   46.54%   +0.02%     
===========================================
  Files          194      194              
  Lines         4890     4890              
  Branches      1262     1200      -62     
===========================================
+ Hits          2275     2276       +1     
- Misses        2527     2528       +1     
+ Partials        88       86       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.