Add RBAC to Terraform provider

### Is your feature request related to a problem? Please describe.

For a self potential hosted customer mentioned there is a fear of having to re-setup all the RBAC e.g. in the event of loss of data, they would prefer to do this as infrastructure as code.

### Describe the solution you'd like.

Add the ability to define users, groups, roles and permissions via Terraform.

### Describe alternatives you've considered

Some form of import / export though Terraform was mentioned as the solution / seems to make sense.

### Additional context

_No response_