Changes

smdpp_Tests/ES2Plus_Tests: move ES2+ code to smdpp_Tests.ttcn

In smdp_Tests.ttcn, the ES9+ and ES2+ interface are intermingled. This
is a problem since ES2+ and ES9+ are two independed interfaces and they
may use different certificates and may even be reachable under a different
FQDN from a different network interface.

To untable ES2+ and ES9+ we can move the ES2+ code from ES2Plus_Tests.ttcn
to smdpp_Tests.ttcn. Since ES2Plus_Tests.ttcn inherits from smdpp_Tests.ttcn
the ES2+ code will still be available to ES2Plus_Tests.ttcn.

This change will add the flexibility of ES2Plus_Tests.ttcn to
smdpp_Tests.ttcn. This means we can now freely configure the FQDN and the
certificates used with ES2+.

Related: SYS#7339
Change-Id: Ib59568379a9d454ea99d66550d6da8fd203681db