Update to Godot 3.5.3, code improvements and more

As "promised", the game has now been updated to Godot 3.5.3.

A few changes have been made, some for fun and others because of version update issues.

All 3D animations had to be remade, so there will be some differences there. Almost every sound's volume was also lowered, and the lighting was changed.

DOF was added and the breathing/walking animations have been changed.