[rush] Add auditing in rushstack CI/CD to catch performance regressions

[dmichon-msft]

Summary

We should add a benchmark test project that runs various common scenarios for Rush, leveraging V8 code coverage to collect information on:

item	unit	source
Executed Code	KiB	V8 Code Coverage
Unused Code	KiB	V8 Code Coverage
Loaded Code	KiB	V8 Code Coverage
Loaded Files	#	V8 Code Coverage
Duration	ms	time / cpuprofile

Once we have this data being generated, we should have a baseline CI pipeline that calculates a new reference value for every commit into main, and then have the PR CI job do performance comparisons and look for regressions/improvements. This will help us catch performance regressions and give us a standard for evaluating impact of optimizations.

This is the same concept as #5690 , but targeting @microsoft/rush.

Candidates for benchmarking:

• rush --help
• rush check
• rush change --no-fetch --verify (--no-fetch is important to avoid externalities, and should really be the default)
• rush install (after having already installed, we're checking the "nothing to do" state)