Added support for changeable SwiftUI .keyboardShortcuts, based on the…

[scornflake]

This adds support for SwiftUI menu items (they now auto update when shortcuts are changed).

Also; it won't throw up a UI when modifying the existing shortcut. The implementation ... isn't great (it relies on comparing the instance points of NSMenuItems), but I can't find any other alternative where I can correctly identify that a SwiftUI generated NSMenuItem is related to a given shortcut.

• Added support for changeable SwiftUI .keyboardShortcuts, based on the work done by @mbenoukaiss
• Modified RecorderCocoa so that it doesn't show a dialog if we are reassigning one of our own menu items