Issue #3458422 by mstrelan, smustgrave: Add string return typehints to protected test helper methods

Issue #3420401 by alexpott, catch, Spokje, smustgrave, quietone, longwave: StandardPerformanceTest fails randomly on MySQL and consistently on Postgres

Issue #3352851 by catch, Fabianx, mondrake, xjm, alexpott: Allow assertions on the number of database queries run during tests

Issue #3352459 by catch, Bhanu951, Wim Leers, smustgrave, Fabianx, heddn, alexpott: Add OpenTelemetry Application Performance Monitoring to core performance tests

Issue #3346765 by catch, heddn, Akram Khan, Wim Leers, mondrake: Add PerformanceTestBase for allowing browser performance assertions within FunctionalJavaScriptTests