Add netconf streams

Add netconf streams

Currently netconf has CSIT jobs for only one stream, 'master', hence
no system integration tests are run for the stable branches.

Add the test jobs for other supported streams, potassium & calcium,
and rename 'master' to 'scandium' to make the naming consistent with
other CSIT jobs for MRI projects.

This patch also introduces 'integration-distribution-branch' to the
job-templates such as 'integration-distribution-test-{stream}' that
triggers downstream CSIT jobs. This allows the netconf CSIT jobs to
be run for its own karaf artifact or the karaf artifact created by
integration/distribution based on KARAF_VERSION & DISTROBRANCH.

Change-Id: I961d0d5230726fcb5bcc13de9e6bef8a354c53bb
Signed-off-by: Sangwook Ha <sangwook.ha@verizon.com>