Workaround for UnauthorizedAccessException in System.IO.Directory.GetDirectories

[Lisias]

As it's happening here, on support: https://github.com/net-lisias-ksp/KSPAPIExtensions/issues/12#issuecomment-988232621

Steam, by some reason beyound reason, decided it's a good idea to shove symbolic links to restricted directories inside user's $HOME. Go figure out, I could not.

While I strongly believe GetDirectories should do the job itself besides this, a workaround is simple enough:

• https://stackoverflow.com/Questions/172544/ignore-folders-files-when-directory-getfiles-is-denied-access
• https://stackoverflow.com/questions/37441459/unauthorizedaccessexception-with-getdirectories
• http://www.blackwasp.co.uk/FolderRecursion.aspx
• https://docs.microsoft.com/de-de/dotnet/csharp/programming-guide/file-system/how-to-iterate-through-a-directory-tree (God save the Google Translator)

Do it ASAP, and propagate this fix on DOE, TweakScale, KSP Recall and KAX.

[Lisias]

TweakScale Support ticket TweakScale/TweakScale#209 is indirectly related to this one.

[Lisias]

Another user was hit by this problem on Forum.

KSP.log.zip

[Lisias]

Perhaps a Quick&Dirty hack about the problem would be to avoid somehow running on /home/<USERNAME>/.local/share/Steam/steamapps/common/ ?