Find additional apps to add to the privacy block list

[pgcudahy]

Thanks very much for the great app. I would appreciate the following feature.

Citrix remote desktop software stuffs some apps in /Library/Application Support/Citrix Receiver like 'Citrix Viewer.app' which I use for work and need to block from recording. It looks like the privacy settings screen only lists apps located in /Applications and /System/Applications. I can try a pull request but this feature requires searching directories in '/Library/Application Support recursively and since I don't know swift I think I would mess that up.

To Reproduce
Steps to reproduce the behavior:

1. Go to Settings -> Privacy
2. Citrix Viewer is not listed in "Installed Apps", thus can't be blocked

Expected behavior
The installed apps list would include apps from /Library/Application Support