Optimizer fixes, mutithreaded benchmarks, grader configurations set to optimized defaults, fixed Linux build issues, fixed binary body grade action

Extracted configuration logic to a standalone project, upgraded all projects to C# 8, implemented static nullability checking

Long-term volume variations module, default grader settings tuning, module loader cache refactorization

Graders - Clipping, Cutoff, Noise, more error checking / logging on the Grade REST endpoint, added logger injection support to modules, removed DummyGrader