Bind multiple keys to same action

[alederer]

Use case:

pretty typical to use different hotkeys in different situations, or on e.g. different keyboards (I use cmd+up/down/left/right for large cursor actions for example, but I'd like to keep the PageUp/PageDown versions around), or to allow same defaults to support users with varying expectations.

I'm not as excited about it as I was at one point, but it still seems like a nice-to-have for a typical tool, and a must-have for a mature or power-user-friendly tool. The change is also not too complicated.

Implementation:

• store action keys as vectors of ints rather than as ints, taking advantage of DivConfig's existing (unused?) ability to save/load vectors of ints. "0" shouldn't be stored anywhere (e.g. no bindings would be an empty vector). a single value of "-1" is used to indicate "not a binding", like how it was previously
• update uses of getKeyName in menus to show multiple keybinds in menus (i think this is the standard, rather than showing e.g. just the first)
• update Keyboard settings menu to show "+" to add additional keybinds
• added an "x" button to remove keybinds rather than just using right-click (it's more important to be discoverable now, since users now have a good reason to remove keybinds rather than merely replace them)

Caveats:

• i think we could now add a bunch of alternate keybinds to help new users get up to speed (e.g. ctrl-up/down for coarse cursor movement, since most laptop users won't even have page up/down), but we would want some logic to prevent new defaults from conflicting with old custom bindings...
• the bindSetActive/bindSetPending stuff feels a bit brittle in general, i wouldn't be surprised if i broke it in some subtle way, but i've resolved all issues i've been able to find

Pics:

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[Eknous-P]

has this been tested for the Ctrl key?