Add performance regression tests and performance reports to CI

[isaaczinda]

[Depends on lightstep benchmarks]

• Add regression_test job to CI to perform rudimentary performance checks on the tracer on each commit
• Add make_cpu_graphs, make_dropped_graphs, make_memory_graphs, and make_disconnect_graphs which generate graphs illustrating the tracer's performance. These jobs only run when manually approved because they take ~20 minutes.
• Fix indentation in CI config