Since some clients use different format of client id not only uuid,
so Zaqar will support this function.
Add one option 'client_id_uuid_safe' to allow user to control
the validation of client id.
Add two options 'min_length_client_id' and 'max_length_client_id'
to allow user to control the length of client id if not using uuid.
This also requires user to ensure the client id is immutable.
Implements: blueprint remove-format-constraint-of-client-id
Change-Id: I96bc2620b09394419b66a733484ff3d8f0d56313
fff82e7a11