New metric: Davies bouldin score #5638

Job	Run time
check-code / mypy	2m 36s
check-code / pre-commit	1m 4s
check-md-links / markdown-link-check	57s
check-package / init-store	13s
check-schema / schema	19s
check-package / pkg-build (ubuntu-latest)	35s
check-package / pkg-check (ubuntu-20.04, 3.8)	1m 12s
check-package / pkg-check (ubuntu-20.04, 3.10)	1m 23s
check-package / pkg-check (macos-11, 3.8)	2m 39s
check-package / pkg-check (macos-11, 3.10)	2m 44s
check-package / pkg-check (windows-2022, 3.8)	3m 37s
check-package / pkg-check (windows-2022, 3.10)	3m 13s
check-package / pkg-guardian	1s
	20m 33s

Provide feedback