feature: client asset hot reloading

[pandinocoder]

Is your feature request related to a problem? Please describe.
In conjunction with #1136 and #1137 it would be strongly beneficial to be able to modify textures and other assets and have Intersect reload them automatically instead of having to restart the client every time a change is made.

Describe the solution you'd like
All textures, audio tracks, fonts and shaders should be hot-reloadable, and the client should be crash tolerant.

Additional context
This feature should be build-toggleable with the compile flag INTERSECT_HOT_RELOADING, so that developers can distribute games with this feature compiled out if they so choose.

[WeylonSantana]

thank god and you too