Is your feature request related to a problem? Please describe.
While playing on a server called Wynncraft (a MMOPRG server) we commonly use a mod called Wynntills that allows us to view the map, cast spells easily, track quests easily. There is already a mod called Controlify Wynn that adds compatability with the server, but while i was remapping keybinds to which i desire i realized a really important feature missing, combo mappings.

Describe the solution you'd like
Being able to map 3 keys being pushed at the same time to trigger a command. To confirm the mapping is done you press the "GUI Abstract Action 1" key down.

Describe alternatives you've considered
I believe there isn't a alternative for combo mappings.

Additional context
Not just for the server that im playing on but this would open so many posibilities for modded controller support. For examble Xaero's Minimap you can have LB + up to open your map, LB + down for quick waypoints. Or for Backpacks mod you could have RB + X to open your backpack, etc. Even for core Minecraft gameplay, you can have stuff like Open Advancements set to LT + down or Toggle Perspective RT + LT something like that if you are interested.

Duplicate of #226