[repository,tests] use the new connection api (part 1/2)
`add_info` should not play with the cnxset nor the mode.
Static analysis showed that:
* add_info is an internal api called with a non-none cnx.cnxset and
also in write mode
* only the altered test violated this assumption, which is now
somewhat documented
sync_schema_props_perms(('State', 'state_of', 'Workflow'), commit=False)
sync_schema_props_perms(('State', 'name', 'String'))