Add base::Move support.

[aee-google]

b/316404107

[codecov[bot]]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (61c20a2) 58.53% compared to head (3bb0c9a) 58.55%. Report is 16 commits behind head on main.

:exclamation: Current head 3bb0c9a differs from pull request most recent head 680bc25. Consider uploading reports for the commit 680bc25 to get more accurate results

Files	Patch %	Lines
starboard/shared/posix/impl/file_rename.h	76.92%	3 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2276      +/-   ##
==========================================
+ Coverage   58.53%   58.55%   +0.01%     
==========================================
  Files        1904     1906       +2     
  Lines       94522    94538      +16     
==========================================
+ Hits        55328    55355      +27     
+ Misses      39194    39183      -11     

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[andrewsavage1]

I'm worried about introducing a new starboard API for this—I was hoping to just have base::Move fail if we were moving a directory and otherwise basically just call base::CopyFile then base::DeleteFile so we would not have to change the places where base::Move is used (afaics the only places where a directory is moved is in a unittest?). That said, this is a much better long term solution, and I assume at some point we'd want to fully implement the functionality the more Chromium elements we take (as I assume the directory moving functionality is used elsewhere upstream).

@y4vor, do you have any thoughts on introducing a new Starboard API for this? Are there security implications that might disallow this for Starboard? Should we instead be adding the posix rename function to the API?