Brains Update - Campfire animation & Quality of Life additions

This update brings a lot of much needed adjustments I've been meaning to add for a while now!
Changes include:

1 ) Mutation reworks:

- Throne Butt: Changed from "FASTER FOCUS - TARGETS FIRE SLOWER PROJECTILES" to "FASTER FOCUS - PROJECTILES HOME TOWARDS TARGET". Brains' projectiles will now arc towards enemies you focus, and the focus' speed increase has been slightly reduced. This change was made since the previous secondary effect wasn't impactful enough: a lot of enemies weren't affected by it, and the nature of focus temporarily affecting only one enemy at a time meant it usually wasn't noticeable enough. The new secondary effect actually allows for new strategies, and thus the focus speed boost no longer needs to be as blisteringly fast to compensate for the lack of impact (though the speed boost is still intended to be both a positive and a negative change).

- Ultra A: Reworked to increase the crit rate maximum to 200%, allowing Brains to essentially get critical critical projectiles past 100% crit rate. This change was made to slightly tone it down whilst also making its effect feel more earned. It's probably still broken tho lol. Furthermore, double crit projectiles are now pink and emit a unique particle effect to differentiate them more.

- Ultra B: Now properly applies directional force to enemies, and has a much cooler looking lightning effect!

2 ) Quality of Life and other additions:

Focus:

- Added a brief window of time where enemies are still selectable to focus after the cursor is no longer hovering over them. This should make it a lot easier to use when playing with controllers! 

- The yellow focus bar is now highlighted when actionable

- Changed the focus success sound effect, and added sound effects for hitting and killing targeted enemies to add a bit more oomph (still using pre-existing sound effects though)

- Reworked the focus code to be a tad more clean. Previously stored the focused target's id in an array because of a scrapped idea for a throne butt/ultra that would have let Brains focus multiple enemies.

- Oh I also fixed a problem where the timer indicator on the target didn't actually work properly without Throne Butt. Oops.

Brain Drops:

- Modified brain drop behavior to be more inline with regular pickup drops, which includes better wall collision and being attracted to the player regardless of distance if a portal exists.

- Crown of Haste now has an effect on them by halving their despawn timing and adding +5% more crit rate.

3 ) Sprite reworks:

Changed a few sprites I was unhappy with: Ultra A & B icons, Skin Loadout icons, Map icons, and death sprites.

 4 ) Campfire animation:

Added a campfire animation! For some reason that took the longest time to work on. Campfire animation code was stolen from Lettuce's (lettusce) Moloch, which was in turn stolen from McChomk's Badlands. Thank you both!