Fedora:
"WARNING: QtWebEngine won't be built. Python3 html5lib is missing."
Ubuntu 20.04:
Curl not found for nodejs

Change-Id: Ic35aee309f25be20a8934b5033e3fe3ea0a8b6c0

Python2 is removed from Debian stable/unstable and
latest Ubuntu. So, we need to use a newest version of
Qt (here Qt 6.4.3).

Change-Id: I6c8b1eee644aab787d54e467f64011762ffd7548

This patch moves already existing packaging scripts from jami-project
into client-qt.
Introduced changes are:
+ WITH_SUBMODULE must search in system lib too because for
packaging client-qt (for rpm) will be built separately, and will
depend on jami-daemon.
+ Fix appdata.xml (replace old wiki with docs.jami.net)
+ path changes (because we build in client-qt not jami-project).

GitLab: #853
Change-Id: I1313830d85c8094fcbcc52e22033a2add7b1e89f