Changes

jobs/ttcn3: move ttcn3-ns-test to testenv

Move ttcn3-ns-test, ttcn3-ns-test-sns, ttcn3-ns-test-sgsn-sns to
testenv. Add -latest and -asan variants while at it, as this is now
supported.

Keep ttcn3-ns-test-fr docker-playground based for now as this currently
requires running on a debian 10 based node (see OS6494#note-18).

Change-Id: I50c56484754255830ae93a3e2afa884d50d86742