When multiple collisions occured in the same frame, Unity overrites their Collision Object of the OnCollisionEnter and OnCollisionStay methods with the latest collision. Since the Collision object is an reference type, the last collision got solved twice, while the second last collision got not solved. This bug is fixed now.

Also add clean code

Performed debugging to understand the impact of the timestep on constraint solving

Cloned the main branch from the repository GuidewireSimulation since this repository was for some reason having authentification problems.