Upgrade macrobenchmarks setup, add CPU / RSS utilization overhead measurements

[ddyurchenko]

What does this PR do?

Updates env variables for Go macrobenchmarks, so they match the new setup from BP PR 74.

Motivation

The changes in this PR and linked BP PR 74 together do next:

1. Enabled RSS and CPU utilization overhead measurements.
2. Simplified LOAD_TESTS variable.
3. Separated benchmark runs into normal_operation and high_load phases more cleanly, allowing e.g. to track Linux load averages, system RSS / CPU usage, etc. during normal load and stress load separately.

Also, Go benchmarking dashboard was updated, so new measurements are visible.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.

Unsure? Have a question? Request a review!

[nsrip-dd]

Thanks!

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-06-27 12:27:35

Comparing candidate commit fdd8c9e in PR branch ddyurchenko/update-macrobenchmarks with baseline commit 5fcda9f in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 47 metrics, 0 unstable metrics.