Merge branch 'irinabron/510170-3-loop-db-stats' into 'master'

Loop through Dbs to gather pg data

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/181580



Merged-by: Simon Tomlinson <stomlinson@gitlab.com>
Approved-by: Simon Tomlinson <stomlinson@gitlab.com>
Reviewed-by: Simon Tomlinson <stomlinson@gitlab.com>
Co-authored-by: Irina Bronipolsky <ibronipolsky@gitlab.com>