Global Toggle hotkey

[emilyavi]

added a global override toggle because while this mod is really useful, i find that in creative mode or during some builds it tends to get in the way. also added a config option (on by default) for displaying a message when the override key is pressed while the mod is toggled off in case the user forgets about the state of the toggle.

other changes in the PR (feel free to pick them as you will, i'm not very experienced with modding so i might have changed something that was done on purpose):

• updated gradle to 8.3 (for java 21 support, i didn't go higher just in case there are compatibility issues)
• updated loom to 1.5
• removed redundant getInstance() calls on client (client was already being passed to the listener)
• removed null check assertion for client.player (ClientPlayerEntity is marked as Nullable which should mean that null is a valid state)
• added TODO strings to the German translation (they probably should be removed/replaced before a new release but the TODOs make it easy to find missing strings)
• updated the readme

[DasHomi]

Ok, first of all, sorry for not responding earlier. I've tried the toggle now, and it seems to work quite nicely, so I'll merge it soon (after I've merged #54). Also, I think this pr implements most of #59, so if you find the time you could also try to implement the game mode checks for creative and spectator mentioned in #59.

[emilyavi]

awesome!! i'll see what i can do hopefully later today