Clean up namespaces #294

Job	Run time
build (windows-latest, Debug)	5m 28s
build (ubuntu-latest, Debug)	3m 38s
build (macos-latest, Debug)	2m 19s
build (macos-latest, Release)	1m 41s
build (ubuntu-latest, Release)	4m 16s
build (windows-latest, Release)	5m 51s
publish-coverage	0s
	23m 13s

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