Enable postgres monitoring on CI

The monitoring of postgresql with program pgwatch2 has been enabled on our CI server, according to tutorial in file scripts/db-monitoring/readme-monitoring.md. You can find statistics at http://hive-4.pl.syncad.com:30000/, and management UI at http://hive-4.pl.syncad.com:8080/.

The monitoring is working in "basic" mode now, and it is enabled for all databases with names matching regex ^hive_.+ (pgwatch2 continuously discovers new databases for montioring). Monitoring in "full" mode can be enabled after installing needed extensions and functions into particular database. This will happen after merging code from this MR into develop branch and then into feature branches. It must be enabled manually at http://hive-4.pl.syncad.com:8080/, by setting "Preset metrics config" to "full_influx".