Fix inputs handling in FixedUpdate

[cBournhonesque]

Pre-requisite knowledge:

• JustPressed becomes Pressed in a system that runs in PreUpdate (so once-per-frame).
• leafwing systems do not run in FixedUpdate
• lightyear handles inputs in FixedUpdate, to have access to tick information

Basically the problem is that:

• if you use just_pressed in FixedUpdate: you can have frames where FixedUpdate doesn't run, so the JustPressed becomes Pressed and just_pressed() misses the input
• if you use just_pressed in Update: I actually cannot remember the exact problem here.. I think it's that the tick-number in Update is not reliable. There's no guarantee that it would be the same as in the server, so you might get off-by-1 errors.

The solution to use pressed in FixedUpdate and consume the action. I think it works, but it generates more diffs than necessary (wasted bandwidth) because of some leafwing issue

Relevant leafwing issue: bevyengine/bevy#6183

[cBournhonesque]

This is now fixed, handling inputs in FixedUpdate should now work as expected