Manually deleting a user / cluster & recreating with the provider results in `Error: user does not exist`

[sherifkayad]

First of all, thanks for this awesome provider!

Unfortunately there's a slight edge case that the provider can't handle well and that's the manual deletion of users from the database(s) or e.g. dropping the whole cluster and re-creating it. In that case the provider complains with Error: user does not exist.

Would be really great if the provider can handle this edge case.

Thanks in advance.