Speedup integration testing pipeline

[fzhinkin]

Speedup integration tests execution by:

• enabling parallel test suite execution (also added an option to ignore JMH lock file, otherwise benchmarks won't run concurrently);
• split the biggest suite into several classes to exploit parallel execution;
• reduced iteration times for benchmarks;
• switched to debug builds for test benchmarks to reduce compilation times.

As a result, on Windows (which is the slowest platform w.r.t. tests execution) build times were reduced by approximately 15 minutes.