Sync monitored folders

Just a simple menu item so we don’t need to enter the preferences if we add files to monitored folders while Audirvana is running.

Better yet would be actively monitoring the folders.

As this relates to our Tree Folder discussion, I’ll +1 this. Having a single monitored folder that Audirvana monitors and optionally imports the files into the Main or Default Library (with chosen folder / file naming) would be very convenient and save users a lot of time.