[FileBrowser] Allow setting startup directory

[TonCherAmi]

Adds a new option - -file-browser-directory that allows specifying the file browser startup directory.

Closes #1259

[codecov-commenter]

Codecov Report

Merging #1325 (41e1fde) into next (12b2b38) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             next    #1325      +/-   ##
==========================================
- Coverage   32.74%   32.72%   -0.02%     
==========================================
  Files          42       42              
  Lines       12136    12143       +7     
==========================================
  Hits         3974     3974              
- Misses       8162     8169       +7     

Impacted Files	Coverage Δ
source/dialogs/filebrowser.c	0.00% <0.00%> (ø)
source/xrmoptions.c	19.93% <ø> (ø)

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[DaveDavenport]

Thanks!

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.