Fine-grained sharing of database connections

Describe the solution you'd like

As of now, database connections can be shared with either none or all users. It would be useful to be able to share database connections only with selected users.

In my case, some maintenance tasks must be performed manually on the database. I would like to add database connections that use PostgreSQL roles with the required permissions and share them with the respective authorized pgadmin users. Then, the users can log into pgadmin using OAuth2 and access the database with their respective permissions without access to database credentials.

For compatibility with existing installations, it would probably be best to not re-purpose the notion of ‘roles’ and instead implement user groups to which users can be added. Then, database connections can be shared with selected groups.

Describe alternatives you've considered

Alternatively, users could log into pgadmin with PostgreSQL roles, bypassing the user management of pgadmin (this was suggested in #6939).

Additional context

Similar proposals have been put forward in the past, e.g. #5534

I would be willing to try and implement this if it gets approved.