fix(NcActions): improve performance by only computing popover maxHeight on demand

[Antreesy]

☑️ Resolves

• Alternative to fix(NcActions): handle expensive height computation by popover library #7778
• Move maxMenuHeight from computed to method
• Only compute bounding rect when required, and not constantly listen to it

🖼️ Screenshots

🏚️ Before	🏡 After

🚧 Tasks

• ...

🏁 Checklist

• ⛑️ Tests are included or are not applicable
• 📘 Component documentation has been extended, updated or is not applicable
• 2️⃣ Backport to stable8 for maintained Vue 2 version or not applicable

[codecov]

Codecov Report

❌ Patch coverage is 12.50000% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 51.41%. Comparing base (eaf4a03) to head (726acfd).
⚠️ Report is 18 commits behind head on main.

Files with missing lines	Patch %	Lines
src/components/NcActions/NcActions.vue	12.50%	3 Missing and 4 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7808      +/-   ##
==========================================
- Coverage   51.58%   51.41%   -0.18%     
==========================================
  Files          96       96              
  Lines        3148     3147       -1     
  Branches      865      868       +3     
==========================================
- Hits         1624     1618       -6     
- Misses       1276     1279       +3     
- Partials      248      250       +2     

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[ShGKme]

Awesome

[Antreesy]

/backport to stable8