Trivial refactor of get_user_bridge function

Add get-irc-connection-info adhoc command

fix #3171

Handle forced-join by just sending an invitation

fix #3116

Fix the muc#traffic response

Was completely broken, and the test was just useless

Remove a potential nullptr dereference, on mam queryid

fix coverity CID 153376

Respond to muc#traffic requests

fix #3069

Make version requests work with global user JIDs as well

fix #3210

Implement result-set-management for LIST queries

ref #2948

Re-add the ad-hoc command the was removed by mistake in the previous commit

Thank you, e2e tests

Add AdhocCommandHandlers::add_command to simplify the usage of this class

And make things a little bit clearer

Look for uuid/uuid.h instead of just uuid.h

Avoids a conflict between /usr/include/uuid.h and
/usr/local/include/uuid/uuid.h on freebsd

Respond to disco#info requests on IRC server JIDs

This makes it possible to execute an ad-hoc command on a server, with
clients like Gajim, for example.

Some little style/typo fixes

Add 2 missing namespaces in our disco#info result

MAM results can be filtered by start and end dates

Respond to MAM requests on a channel JID

At the moment, result-set-management is not implemented, the whole history
(well, at most 1024 messages) is returned.

Add a global configure ad-hoc command, with max history length

Forward IRC invites to XMPP

On a client error, do not QUIT, just make the resource leave all channels

This should fix #3205

Forward mediated invitations (XMPP to IRC only)