CSS-7347 Ranger usersync

[AmberCharitos]

Adds the Ranger usersync charm function:

• Additional configuration values
• Ranger usersync install.properties
• Ranger usersync integration test with OpenLDAP charm

Additionally adds:

• Structured config to manage config validation
• LDAP optional relation handler. If the openldap charm is related it takes these values provided if not then it uses config.

Refactors:

• Integration tests to decouple the Trino integration testing from the other tests.

Removes:

• Old method of synchronisation through Unix users and configuration file

[mertalpt]

On a second thought, previous comments are minor enough that I can just approve.

[kelkawi-a]

LGTM