Minor Balance Patch for Demo and Beta builds

This new build has a number of crash and bug fixes, polish for the UI, and balance changes for campaign mode. Some of the changes only affect the content available in the beta build, but many of them also apply to the public demo.

If you notice any bugs or have any feedback on any of these changes, please let me know! I am much faster at responding on the Discord: https://discord.gg/v8tzYfX8yr

Balance Changes:

• A number of Campaign Challenges that were inaccessible in the Beta build have now been enabled. All 16 should now be available to play.

• The Penny Pincher item that increases you damage based on how much gold you have has been nerfed from 1 damage per 30 gold -> 1 damage per 50 gold.

• One-time use items like the Helmet, Armor and One-Up will now return to your critters in the next match. They remain in your loadout with a cracked and desaturated icon so you know they are still there. As a result, their cost in the shop has also been brought up to match other items of their rarities.

• Enemy spawn groups containing Aura enemies used to spawn multiple auras, making them too oppressive. Now the group will only have 1 aura and the backup critters will have items to get extra benefits from the aura.

• I added logic to control the initial spawn distance of enemies in the campaign based on their archetype. Now snipers will only spawn at a distance and the runts will only spawn closer to your critters.

• Reduce the damage dealt by the runt enemies. They are meant to be a rushdown group, but they were 1-shotting the player's critters too easily.

• Removed the firework from the Boss's weapon pool because it was not threatening and often lead to self-damage.

• Decreased the likelihood of the Grenade appearing in the starting loadout. It's a powerful weapon, but more situational, so it hurts having 2 in your starting loadout.

• Made minor adjustments to the tutorial level layout and increased the tutorial enemies' miss chance.

Polish:

• Added a "Random" option to the Versus mode's Critter Selection. CPUs now default to Random. This makes it easier to swap critters when you have 4 players, since there cannot be duplicates.

• Items earned in Campaign mode will now also be granted in Versus mode.

• Added a new screen transition effect.

• Added an animation and sound to fullscreen popups.

• Added a Fade effect on background objects that would often obscure the play area.

• Critters' pupils will shrink when they play their "scared" facial expression.

• The grenade, proximity mine and mortar all have a new charging sound effect. When a charged weapon reaches full charge, it plays another sound to indicate it's full. There's also a sound when you cancel the charge.

• Added an option to Invert Camera X based on requests.

• The critter head icons now fade when that critter has no actions remaining, making it easier to tell who can act at a glance. You can still click on them to jump straight to that critter.

• If you single-right-click while a critter is selected, it will deselect.

• When enemies spawn in, they will have their see-through-walls effect on so it's easier to see where they spawn.

Bug Fixes:

• Fixed the issue where panning speed when the camera was looking straight down would be too slow.

• Fixed a crash when surrendering while an enemy is shooting.

• Fixed a crash that happened when enemies would die as a