ims_registrar_scscf: fix crash caused by an uninitialized AVP
(cherry picked from commit 52d727dc249a88b31348b008045cc6071ab215a7)
Improved Free at cscf_get_service_route(), caused a reproducable crash
(cherry picked from commit caa9954d3c017ce741245d8f2b338158caf2270f)
ims_registrar_pcscf: Bugfix: Properly handle the case, when we do not have a Asserted Identity
(cherry picked from commit 6b0bcff43c0b3c22f399211aeb7e9279f7c35814)
lib/ims: Replaced custom getter for P-Asserted-Identity with the Parser from Core
(cherry picked from commit af1734cea213b2a07c9d725fff158cd4899725d1)