mam: Send “fin complete” only when appropriate

Also simplify how we did the whole “limit + 1”
And fix one bad interpretation of the XEP for the case where the query has
no after or before restriction.

fix #3349

Revert "Use a different Date data type"

This reverts commit 857c7d3972a03cbeebf730d99b924d3710dee6a0.

Revert "Use the Date to find a next page in RSM, not the id"

This reverts commit 5ef7ba08028065b03d51d1dc70bb35aeb41ae19d.

Use jid.bare() instead of manual concatenation

Use the Date to find a next page in RSM, not the id

This way, it works, whatever the order of insertion in the database was.

fix #3343

Use a different Date data type

PLEASE backup your database before testing this commit, and report any
migration issue.

In postgresql, we use timestamp with timezone.
In sqlite3 we use REAL (the date is expressed as julianday)

This requires a migration of the muclogline_ table:
In postgresql it’s pretty simple, we convert all the integer into timestamps

With sqlite3, we actually rename the table, create the new one with the
correct type, then copy everything to the new table, with a conversion
function for the Date_ column, and then we delete the old table.

fix #3343

Send the stanza-id for messages received by other users

fix #3347

Properly handle force-join presences by sending everything in return

fix #3305

Pass an IrcClient* to send_muc_leave instead of doing an other search

Add a nick field in the IRC server configuration form

fix #3317

Don’t reflect an empty id if it was not included

Instead, generate a uuid for that message

Reflect message IDs in channel MUCs

fix #3283

Add a <item/> node in the presence of a leaving participant

fix #3339

Remove the virtual channel feature altogether

Use the same function for both history orders

Always return the oldest matching messages from MAM, even if no date is set

Add a <x muc#user> node on outgoing private MUC messages

See https://xmpp.org/extensions/xep-0045.html#privatemessage

fix #3321

Merge branch 'postgresql' into 'master'

Add postgresql support

Closes #3237

See merge request louiz/biboumi!18

Run some of the ci tests against a postgresql docker container

Fix #3304