Pixel collision detection

[MysticQuest]

Description:
Pixel collision is meant to run only when AABB collision is detected between two objects.

Misc information:
CollisionSystems.cpp already contains a couple of pixel collision functions that are never called.
They were implemented at some point but pixel collision was not accurate and attempts to fix it broke the textures so it was suspended for the time being.

PixelCollision

PixelIsSolid

Goal:
Fix pixel collision (duh) and run it inside AABB detection.