[db-api/configuration] simplify db-api and configuration so that all the connection information is in the repository url, closes #2521848
eg no more specific option of pyro ns host, group, etc. This also fixes broken ZMQ
sources.
Changes:
* dropped pyro-ns-host, pyro-instance-id, pyro-ns-group from client side config, in
favor of repository-uri. No migration done, supposing there is **no web-only config**
in the wild. Also stop discovering the connection method through the repo_method class
attribute of the configuration, varying according to the configuration class. This is
a first step on the way to a simpler configuration handling. Notice those pyro options
are still available for repository only / all-in-one configurations as they are needed
to configure the pyro server.
* stop telling connection method using ConnectionProperties, this is so boring. Also,
drop _cnxtype from Connection and cnxtype from Session. The former is replaced by a
is_repo_in_memory property and the later is totaly useless.
* deprecate in_memory_cnx which becomes useless, use _repo_connect instead
sync_schema_props_perms('CWSource', syncprops=False)