[cwuser] make CWUser callable, returning self for dbapi compatibility In the dbapi, Connection and Session have a ``user`` method to generated a user for a request In the repo api, Connection and Session have a user attribute inherited from SessionRequestBase prototype. This ugly hack allows to not break user of the user method. To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[client-connect] drop rqlst on rset returned client side The DBAPI used to drop the RQL syntax tree on rset to save bandwidth. We could stop doing it for In-memory client connection. However keeping the syntax tree leads to multiple tests failures. So we keep dropping it as the DBAPI always did. related to #2503918

[client-connection] add a repo property for dbapi compatibility To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[client-connection] add a connection property for dbapi compatibility To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[client-connection] add a sessionid property for dbapi compatibility To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[client-connection] add a cursor() method for dbapi compatibility To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[client-connection] add a request() method for dbapi compatibility To ease transition from dbapi to repoapi we need the ClientConnection to be as compatible as possible with the dbapi. Adding this method goes in this direction. It'll get deprecated in the deprecation wave that will conclude the repoapi refactoring. related to #2503918

[repoapi] introduce a basic ClientConnection class This is the new official way to access the repo from client side. It still access Session object directly as the server side connection is not up yet (and it's not up because it would have no user). Multiple follow up commit will install compatibility with the DBAPI. This will ease the migration from dbapi to repoapi. ClientConnection has no user yet but later commit will use it in the whole Web stack. related to #2503918

[req] add a _set_user method RequestSessionBase usally need to recreate a new CWuser appobject linked to themself. We add it to the base class to avoid multiple redifinition.

[server/session] add a login property session.login is a DBAPISession attribute. Having it on server side session will helps the rework of the API to access repository. The new schema drop the concept of DBAPISession and use server side session for the same purpose. related to #2503918