packaging: migrate packaging scripts in client-qt

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