Changes

SIP_Emulation: Rename component id

Remove the dash character, since it makes it impossible to reference the
component name under TESTPORT_PARAMETERS in .default/.cfg files.

While at it, actually, allow the test to provide a full id instead of
always appending the suffix to it. This provides more freedom on the
testsuite to provide a fitting component name.

Change-Id: Iecefe7d98a5842872f1efc55e013f672186ef1a8

asterisk: Initial steps to emulate IMS core

Add the initial infrastructure to manage 2 SIPmsg_PT ports, one for the
local SIP UAs and one for the IMS core.
Still missing:
* Trigger Asterisk (through AMI) to do the initial connect + register to it
* Configure ipsec after Unauthorized response from IMS core

Change-Id: Ibbbadd54b7facf4ef7384499704e742f482a1252

SIP_Templates: tr_SIP_REGISTER(): Pass via field directly as a param

Similar to other templates which already required it.
There's no user of this template (yet).

Change-Id: I9fe477370e028543b04dee35a3285ddae6bb2c59