Descend Happy Ghasts

I had to re-make the mod from scratch as I was foolish enough to code it in regular (payed) IntelliJ and not the community version. I thought I was using the community version until the liscence pop-up came. So yeah I've just been lazy and putting this off until now. Sorry about that :)

-The mod should work the same way it used to.

-Key binding option should be found in the top of the "Movement" category and the speed remains unchanged, aka it matches the default ascending speed of the happy ghast.

-I can't remember if I remembered to patch this in the previous version, but the happy ghast can not store speed by the player holding the descend key and then moving off a block to teleport to the bottom.

Rubber banding might still be experienced on servers, however the speed is so slow I don't think it should matter. I have yet to test the mod on a server, but should this cause issues I will try to fix it.