Feature Request

Handle the EntityAction request in feather/server/src/packet_handlers.rs

Description

This feature request is very similar to #422 but with a lot more values to track.

• Start sneaking
• Stop sneaking
• Leave bed
• Start sprinting
• Stop sprinting
• Start jump with horse
• Stop jump with horse
• Open horse inventory
• Start flying with elytra

wiki
Notice how there is no StopFlyingEvent, so the server is expected to track this value. How this is kept in synch i have no idea. A reasonable first approximation is that we just don't bother with keeping it in synch, as the physics system is still missing #357.
Another noteworthy thing is that the Leave bed packet is not sent by the client if night is changed to day by players sleeping. So a sleep tracking system has to trigger a BedExit event.
Open horse inventory is only sent when pressing the inventory key (default: E) while on a horse — all other methods of opening a horse's inventory (involving right-clicking or shift-right-clicking it) do not use this packet.