Non-rebindable `C-space` binding in pickers is problematic on MacOS

[Omnikar]

On MacOS, ctrl-space is a system binding to switch keyboard layouts. As a result, the "filter options" binding in pickers is inaccessible via the default keybind on MacOS. Since rebinding is not currently available for picker bindings, this action becomes completely inaccessible.

[the-mikedavis]

The C-space keyboard shortcut works for me on Kitty on macos after disabling the system shortcut:

System Preferences > Keyboard > Shortcuts > Input Sources and then uncheck the boxes C-Space and C-Option-Space.

[xcpky]

I'm used to the C-Space shortcut in macOS and I guess the some other Mac users are used to it too. It would be better if we can modify the shortcuts in pickers ourselves or at least the C-space one.

[pascalkuthe]

I think we can close this in favor of #5505