Further hotkey features to implement

[wraitii]

Meta-ticket following r24215.

There are a number of improvements to the hotkeys still possible. i'm milestoning this for A24 but it's a likely pushback.

Feature list (from the top of my head):

• More platform support (e.g. Delete on mac should translate to Backspace, really).
• Give hotkeys a better name and a description so that players aren't confused (cf in-game Manual).
• Better way to categorise hotkeys (right now, it's the name prefix which is not ideal).
• ...?

Bug list:

• The 'no confirm' hotkey doesn't properly work with all combinations, only the first, which means on mac that to kill without confirm one needs to use 'Fn', which isn't needed otherwise.

[s0600204]

• Implement a way of finding the key-combination(s) assigned to a given hotkey (so it may be displayed in a tooltip) that preferably doesn't require the c++ code to iterate through every combination of every hotkey (ref. r24668).

(Feel free to reword)

[wraitii]

In 24699:

Minor Hotkey editor QoL: enable Save on changes only.

This enables the 'save' button only when there is (probably) something to save. It improves the UX of using the editor since it gives feedback that the hotkeys were indeed saved.

Refs #5867

Differential Revision: ​https://code.wildfiregames.com/D3419

[Stan]

​https://wildfiregames.com/forum/topic/36639-a24-feedback/?do=findComment&comment=417646

Of course it's good that one can configure hotkeys now, but this will look very confusing and hard to understand to newbies. In A23 we had descriptions for all the hotkeys, that has gone. Plus, the new surface is not translated.

My suggestion: Bring the description back and implement the autociv-mod, which delivers one additional surface for changing hotkeys.

That the mods autociv and fgod don't work anymore is an unpleasant regression. All mods which are feature mods without changing the game too much could be implemented.

[wraitii]

In 25023:

Customize hotkey categories & ordering, prepare for translation.

• adds JSON files to specify the human-readable categorization, name and description of hotkeys.
• clean up code

Translation support via messages.json not yet added - the strings need another pass and that avoids translators doing redundant work. See D3641

Refs #5867, Refs #5996

Differential Revision: ​https://code.wildfiregames.com/D3596

[wraitii]

In 25097:

Improve & translate hotkey name/descriptions.

Improve the hotkey translations. This adds them to messages.json for translation, closing the work from rP25023

Refs #5867, refs #5996

Differential Revision: ​https://code.wildfiregames.com/D3641