Add a memory usage check

[dblock]

Coming from #2440 and #2441 and similar leaks that we've had in the past, add a tool that compares memory usage before/after a change in pull requests. This could be modeled after https://code.dblock.org/2024/04/19/commenting-on-pull-requests-in-github-actions.html (newer version in opensearch-project/opensearch-api-specification#297).

1. Create a benchmark that causes a lot of memory allocations quickly.
2. In every PR run the benchmark on the before code and the after code, generate some data on allocations.
3. Add a comment to the PR showing the change.