fix(NcRichContenteditable): keep previous cursor position on focus

[Antreesy]

☑️ Resolves

• Since feat(NcRichContenteditable): put caret in the end when focus input #4924 either something was changed in browsers, or wasn't tested in different OS properly
• ATM on Linux, unfocusing page with focused NcRichContenteditable and the focus the page back trigger @focus="moveCursorToEnd" event, effectively setting cursor to the end
• Now, we check if element was previously focused/has a selection range, and keep it as-is
• on Windows, can be tested with $0.blur(); $0.focus()

🖼️ Screenshots

🏚️ Before	🏡 After
B	A

🚧 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 33.33333% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 51.55%. Comparing base (b0a5563) to head (cda15a9).
⚠️ Report is 23 commits behind head on main.

Files with missing lines	Patch %	Lines
...ts/NcRichContenteditable/NcRichContenteditable.vue	33.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7791      +/-   ##
==========================================
- Coverage   51.57%   51.55%   -0.02%     
==========================================
  Files          96       96              
  Lines        3143     3146       +3     
  Branches      863      866       +3     
==========================================
+ Hits         1621     1622       +1     
- Misses       1274     1276       +2     
  Partials      248      248              

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[nickvergessen]

Confirmed to fix the problem in:

• Ubuntu + Chromium
• Ubuntu + Firefox

[Antreesy]

/backport to stable8

[Antreesy]

Confirmed on macOS - Safari