Refactor run_fixture tool, clean up ops #760

Job	Run time
tests (ubuntu-latest, tests)	45s
build (ubuntu-latest, noradio)	1m 59s
tests (macos-latest, tests)	29s
build (ubuntu-latest, wifi)	2m 20s
tests (windows-latest, tests_nosan)	1m 20s
build (ubuntu-latest, bt)	1m 59s
build (macos-latest, noradio)	1m 29s
build (macos-latest, wifi)	1m 47s
build (macos-latest, bt)	1m 59s
build (windows-latest, noradio)	4m 2s
build (windows-latest, wifi)	4m 30s
build (windows-latest, bt)	4m 50s
	27m 29s

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