Problem/Motivation
Core performance test are (somewhat ironically) some of the slowest functional javascript tests in core.
This is because they rely on creating somewhat realistic scenarios (standard and umami profile), and on the chrome performance log which has a lot of quirks. To avoid this, most of the tests only add performance assertions and opentelemetry logging for a single page/operation.
However, since PerformanceTestBase was added, we've fixed a lot of weird performance log timing issues and other race conditions, so it might be OK to try to consolidate things down to fewer methods or one per test class, with more requests/assertions in each.
Doing this for StandardPerformanceTest first since it's the smaller compared to Umami