packaging: Adapt to client-qt vendoring libjamiclient.

For both deb and rpm make jami-libclient a transitional package that
does not have any dependencies and that the user can safely remove.
The jami-libclient package can then be dropped later into the future;
perhaps in a year or so from now.

Change-Id: I53d7cb89a40282acec7b4b0aa7930b1a52835a1b