python-api: sptypes: fix a couple of validation bugs.
python-api: sptypes: fix a couple of validation bugs.

- MAX_CLIENT_ID: remove a misleading leftover obsolete definition
- MAX_{BRIDGE,CLIENT,MGMT}_ID: fix an off-by-one error
- GlobalVolumeId: the cluster ID may be encoded with more than one character

Change-Id: I128bef1ef99fb41068ec1f08789a2b74457bf6d7

storpool/python-storpool