[Feature Request] Share a node's database labels and types with central server

[bartvanb]

Problem description
At present, database labels are defined by node admins and not shared anywhere. If a user runs a task for multiple organizations, they must define a database label that should be present at all nodes, but it is impossible to verify that these databases exist at the nodes via vantage6. It would be helpful to have this information so that we could alert users that the database label they define doesn't exist.

Secondly, it would also be useful to share database types so users know which additional parameters they may need to define (e.g. if a node uses an excel database is should receive a worksheet name to read in).

This is also useful for the new researcher UI we will work on soon.

Desired solution
Share node database labels and types with server using system developed for #12.

[bartvanb]

We should release this in v4.0 because there database labels and types are obligatory

[frankcorneliusmartin]

✅ I found the encryption, allowed_algorithms, database_labels and db_type_default in the database