[FEATURE] Use the user directory before querying the server for a JID

Perform a search in the user directory before resolving the JID in the
service discovery as many servers will not report the JID status due to
security reasons.

Change-Id: Ie96e5685e90b4c09ed5483993b2b150e4a2b0eb2
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/418
Tested-by: Jenkins CI
Reviewed-by: Damla Durmaz <ddurmaz88@gmail.com>
Reviewed-by: Martin Wichner <martin.wichner@googlemail.com>
Reviewed-by: Arndt Lasarzik <alasarzik@gmail.com>
Reviewed-by: Franz Zieris <zieris@inf.fu-berlin.de>