Reduce file and folder lock time

[MeijeSibbel]

Right now both sync-Storj, Sync-Sia and the overlay handler locks all files both during the time the files are first added to the sync directory, when files or folder are edited or when one tries to delete the sync dir content. The problem arises when hundreds or thousands of folders with a/b/c/d/e/f... sub-folder structures with files come into play, as the app can't keep up with the speed at which the user is interacting with the files.

If the app reads the files, it should do so passively in the background, not actively.

Although many errors arise from this, the main problem is the negative user experience impact.

screenshots of the errors are posted in #sia on slack.