[Mac] Keybinding editor doesn't recognise Command key

[viernullvier]

Steps to reproduce:

1. Go to Preferences -> Keys
2. Select Undo
3. Press Add Key Sequence
4. Press Cmd+Z

Expected behaviour:

• Undo would be bound to Cmd+Z

Actual behaviour:

• The Cmd (a.k.a. Meta) modifier is not recognised, Undo will just be bound to the z key

Note: I was about to report a nitpick about the default keybindings not adhering to Mac platform conventions and tried to create and export a keybindings file that could be used as the Mac default when I ran into this issue.