feat: verus flat fly

[liquidsquid1]

adds a simple verus flat fly

the reason this works is verus becomes super dumb when you clip, so blinking with that allows you to infinitely air walk. on top of that, timer works with high pauses inbetween movement packets which means that any timer would work with the blink (as long as you are on 1.9.x or higher)

can rarely flag when moving whilst stopping, but i've set the velocity to 0 to combat that.

tested on anticheat-test AND loyisa

you can only land on the same Y level