Remove EntityType from juju watcher and workaround juju bug for retrieving the status

- The juju watcher was doing an unnecessary translation with the entity types. The entity already provides an attribute .entity_type
- Juju has a bug in version 2.8.2 that returns a wrong status. Therefore, charms were getting stuck in waiting for ever.
Change-Id: I44709190acc41601e8a67f4c52074fda00c3d495
Signed-off-by: David Garcia <david.garcia@canonical.com>