[multi-sources-removal] Drop the "true" multi-sources planner Only keep copy-based sources. This will soon allow for greater code simplification. Related to #2919300

[multi-sources-removal] Drop cw.server.sources.extlite no more used for a while, beside an utility class Related to #2919300

[multi-sources-removal] Move cw.server.sources.ConnectionWrapper where it belongs It's only used by the ldap utilities. Related to #2919300

[multi-sources-removal] Drop pyrorql and zmqrql sources After a few years experementing "true" multi-sources, we're now moving to "copy-based" source à la datafeed. As pyro and zmq sources have no more known customers and the related code is in the way of future refactoring of cubicweb's core, we decided to drop support for those sources without backward compatibility. If you're still using a zmqrql or pyrorql source and you want to upgrade, ask support to move it to datafeed using a pre-3.19 version first. Related to #2919300 (first step)

[web/formfields] Make CompoundField inherit needs_multipart from its subfields If there's a FileField within a CompoundField, the latter will not have the enctype multipart set, even though the FileField needs it. CompoundField should inspect its children fields to determine whether it needs multipart. Closes #3406930.

[wsgi/handler] fix api change from 3.18

[req] deprecate get_cache (closes #3181499)

Added tag cubicweb-version-3.18.2, cubicweb-debian-version-3.18.2-1, cubicweb-centos-version-3.18.2-1 for changeset 6880674c1a26

merge 3.17.12 into 3.18 branch

[editcontroller] fix cardinality computation (closes #3120495)