chore: postres driver allow setting the max number of connection from a parameter

[Ivansete-status]

Description

It is more handy to be able to easily change the maximum number of PostgreSQL connections a nwaku node can handle simultaneously.

Changes

• New wakunode2 parameter: store-max-num-db-connections

[github-actions]

This PR may contain changes to configuration options of one of the apps.

If you are introducing a breaking change (i.e. the set of options in latest release would no longer be applicable) make sure the original option is preserved with a deprecation note for 2 following releases before it is actually removed.

Please also make sure the label release-notes is added to make sure any changes to the user interface are properly announced in changelog and release notes.

[github-actions]

This PR may contain changes to database schema of one of the drivers.

If you are introducing any changes to the schema, make sure the upgrade from the latest release to this change passes without any errors/issues.

Please make sure the label release-notes is added to make sure upgrade instructions properly highlight this change.

[github-actions]

You can find the image built from this PR at

quay.io/wakuorg/nwaku-pr:2246

Built from 8576c4c

[SionoiS]

Thank you!

[gabrielmer]

Looks great! Thanks so much! :))

[jakubgs]

Nice.