fix migration from pre-3.13.1 versions (closes #2846978) Need to check the existence of the asource column before the first call to eid_type_source.

[constraint] more robust unicity constraint failures reporting for end-users Postgres or Sqlserver have limits on the index names (around resp. 64 and 128 characters). Because `logilab.database` encodes the `unique together` constraint rtypes in the index names, we sometimes get truncated index names, from which it is impossible to retrieve all rtypes. In the long run, the way such index are named should be changed. In the short term, we try to reduce the end-user confusion resulting from this design flaw: * in source/native, the regex filtering ``IntegrityError`` message does not impose an `_idx` suffix, which indeed may be absent (the result being an UI message that resembles a catastrophic failure), * also we avoid including a trailing " (double quote) from the error message * in entities/adapters, the well-named ``IUserFriendly`` adapter is made a bit smarter about how to handle missing rtypes. * the adapter also always produces a global message explaining the issue (and the fact that sometimes, the user is not shown all the relevant info) * i18n is updated Closes #2793789

[hooks/security] Streamline attributes default permission check. The current default permission on attributes delegates the check to the entity permission update policy. Since this is already checked it can be skipped. The equality comparison will work, even with a deserialized schema, because the default update perm is:: ('managers', ERQLExpression(Any X WHERE U has_update_permission X, X eid %(x)s, U eid %(u)s)) which will always be deserialized in this order (groups first). However this is a slight semantic change: entity type level 'update' permissions can now be effectively used to encode update-time rules if the default attribute permissions are used (before this change, the 'update' rules at entity type level were fired at creation time). Closes #2930861.

[test/schemaserial] swap got/expected to get nicer unittest2 diagnostics Prepares #2965518.

[repository] drop safe attribute on ``internal_cnx`` People that need to disable hook can do it explicitly anyway.

[dbapi] deprecated the dbapi

[repoapi] deprecate dbapi compat method

[testlib] deprecated the older api to access the repo.

[connection] deprecated free_cnset and set_cnxset

[session] deprecate all Connection related method on session

[session] drop dead _current_cnx_id Not used anymore for a few commit.

[session] privatise get_cnx and close_cnx The only user, repoapi now use ``new_cnx``

[doc] add documentation for the new API in test

[testlib] add an default testcase.adminaccess (and use it for default session) This adminaccess is the new offical way to get connection, and request on a repo.

[testlib] introduce a RepoAccess class to easily create connection and request Each RepoAccess hold a session for a user and three helper function to help create Connection, ClientConnection of WebRequest related to this session. related to #2920299

[repoapi] make ClientConnection.__enter__ return self This allow the standard idiom:: with repoapi.connect(repo, login='babar', passwork='elephant') as cnx: cnx.execute(…)

[documentation] describe repoapi and web side change. Short version explaining what object replace what and that BC existes for a few version.

[testlib] use internal_cnx instead of internal_session internal_session is deprecated.

[repository] add an ``internal_cnx`` method to replace ``internal_session`` Accessing the repo through a Session is deprecated. We need an easy replacement for ``internal_session``. This API change was a good occasion to stop disabling integrity hook by default. This is huge source of bug in user-code. related to #2503918

[connection] enforce that a connection must be open to be used The same than for ClientConnection, we ensure the connection is used inside a its context. .. note:: We may rely on that for ClientConnection and remove de dedicated code in Client Connection but I prefer the current explicite and duplicated version for now.

use standalone Connection to Client Connection

[session] add a new_cnx factory Having user-code importing cubicweb.server.session.Connection is inconvenient. We add a simple factory fonction on the session.

[connection] allow simple instantiation of standalone Connection Such connection will automatically pick a connection id. Note, They are not automatically closed on session close. But they will fails to grab new cnxset once the session is closed.

[connection] handle and explicitly life cycle on Connection Like ClientConnection, Connection object need to be explicitly started and stop. They aims to be used as context manager.

[sesion] distinction between Connection handled by the session and other. Not mixing the new and backward compat approach seems a good idea. Let's enforce it.

[session] replace _clear_thread_storage with close_cnx There is not good reason to keep two distinct method.

[session] explicitly take Connection object in close_cnx Now that ClientConnection explicitly reference and use the Connection object we do not need to use connectionid here. We can safely change this signature, ClientConnection is the only use of close_cnx for now.

[session] drop the Session._clear_cnx_storage method It is just cnx.clear() now.

[session] wrap too long line Too long line is too long. (Confucius 503 BC)

[session] gather close_cnx with get_cnx and set_cnx They do the same kind of operation and deserve to be grouped together.

[client-connection] remove the _srv_cnx usage It does not do anything special now that we use explicite Connection object with automatic cnx_set handling.

[client-connection] explicitly check that the client-connection is open The check is also perform by the _srv_cnx property. But we do not need those property anymore.