Testbed sample for benchmarking

[Genbox]

Create a sample in the testbed that uses as many core parts of the engine as possible. It should be used when optimizing the engine as a benchmark to see if an optimization worked or not. It should also:

• Enable detailed debug view
• Disable sleeping of bodies

I'm thinking the following features should be present:

• A small pyramid to stress test the contact system and solver
• A distance calculation between two polygons
• Time of Impact stress test
• Raycast stress test (might have too much in common with distance test)

[Genbox]

I've created a couple of benchmarks using BenchmarkDotNet and I'm calling the narrowphase and broadphase directly. I plan on expanding it to the solver as well, but it is more involved than the simple APIs with narrow and broadphase.