Represent switch to workspace intelligently

[danirabbit]

Right now all of the keys for the Super 1-9 shortcuts are separate keys. After some discussion with @cassidyjames it sounds like we think we can assume that these keys will be consistent and we should represent it as: [ ⌘ ] [ 1 ] - [ 9 ].

To do this technically, probably the best way to go is to grab and display the key at SCHEMA_WM, switch-to-workspace-1 and then check and see what's the last non-null switch-to-workspace-n key (it goes up to 12) and then display that number