[stable-3.9] Update VFS placeholder each time a file is opened by Word

[backportbot-nextcloud]

Backport of #6010

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

20.5% Coverage
0.0% Duplication

Catch issues before they fail your Quality Gate with our IDE extension SonarLint

[codecov]

Codecov Report

Merging #6029 (a94a918) into stable-3.9 (ea71a79) will increase coverage by 0.07%.
Report is 15 commits behind head on stable-3.9.
The diff coverage is 41.17%.

Additional details and impacted files

@@              Coverage Diff               @@
##           stable-3.9    #6029      +/-   ##
==============================================
+ Coverage       60.44%   60.51%   +0.07%     
==============================================
  Files             145      145              
  Lines           18671    18679       +8     
==============================================
+ Hits            11285    11303      +18     
+ Misses           7386     7376      -10     

Files Changed	Coverage Δ
src/libsync/account.cpp	43.39% <37.50%> (+0.54%)	⬆️
src/libsync/account.h	42.85% <100.00%> (+2.85%)	⬆️

... and 4 files with indirect coverage changes

[nextcloud-desktop-bot]

AppImage file: nextcloud-PR-6029-a94a9185c6ec37e9a030177a43148d288de005e7-x86_64.AppImage

To test this change/fix you can simply download above AppImage file and test it.

Please make sure to quit your existing Nextcloud app and backup your data.