Make plugin compatible with multi tenancy in grails > 3.1

AuthenticationToken resolving doesn't support MultiTenant implementation.
Like:

```java
import grails.gorm.MultiTenant

class AuthenticationToken implements MultiTenant {

Long tenantId
String username
String token

static constraints = {
}
}
```

With this implementation, i get this error on login:
```
ERROR: column this_.tenant_id does not exist
```

Do you have an idea how to solve this plz ?

In my application, User domain class is multitenant so AuthenticationToken must be too.

Start with AuthenticationToken resolution during login and the MultiTenant implementation shown in the issue, then trace why the lookup expects tenant_id. Reproduce the login failure in a Grails application with a multitenant User and AuthenticationToken; done means authentication succeeds without the missing-column error.

Written by the indexing model from the issue text.