Water and minor fixes

Ventury has water, and while the player character doesn't yet have an aquatic state or animations to use, the effects are present. Putting the camera under the surface of the water causes the sound to get a little muffled and warbled, which is neat! There's also some shaders for the water, including a cheap blur effect and undulation of the pixels in the water.

Rixin's eyes were previously rendered as transparent, which caused problems with shaders like water. This should no longer be an issue.

The testing dungeon environment and sanctuary both have improved reverb. Some objects like doors are now also excluded from getting reverb to prevent obnoxious clipping.

A horse object was also added to the game, though she is nonfunctional. Work on getting the player character able to mount, dismount, and ride the horse will be done sometime soon.