[Enhancement] Add ability to run compute shaders in test project

[thargy]

There are lots of subtle differences between the implementations of the different backends that mean we can't guarantee equivalence between compilations unless we actually execute the shader code. Further to the discussion in #65, using Veldrid in the test project should allow us to create compute shaders to automatically flag differences in code execution.

[thargy]

See GH-77 for working example.

[thargy]

This was merged in 9c934c2.