[VOL-5010] - Clone unit tests onto a v2.12 branch

[VOL-5005] - Create a v2.12 release branch for test jobs.
[VOL-5004] - Deprecate voltha-2.8 unit tests

makefiles/release/include.mk
makefiles/release/help.mk
makefiles/release/voltha-versions.mk
makefiles/release/targets.mk
makefiles/release/targets/voltha-certification.mk
makefiles/release/targets/voltha-e2e.mk
makefiles/release/targets/voltha-nightly-jobs.mk
-------------------------------------------------
  o Define make targets to create versioned subdirectories.
  o 'branched' unit test files will live in subdirs.
  o Refactoring still in progress, v2.8 tests are disabled/retired in the interim.

jjb/voltha-e2e.yaml
jjb/pipeline/voltha/voltha-2.12/
jjb/voltha-test/voltha-nightly-jobs/voltha-2.12.yaml
----------------------------------------------------
  o Create versioned subdirectories to support v2.12 unit testing.

jjb/voltha-e2e.yaml
jjb/voltha-e2e/voltha-master.yaml
jjb/voltha-e2e/voltha-2.12.yaml
jjb/voltha-e2e/voltha-2.8.yaml
--------------------------------
  o Guineapig: periodic-voltha-pm-data-test-bbsim
  o Refactor unit test from voltha-e2e.yaml.
  o Create new v2.12 pipeline job.
  o Disable pre-lts legacy pipeline job 2.8
  o Refactoring one test so job state in all branches can be checked.
  o Tomorrow verify the v2.8 job did not launch

Change-Id: Ib550fae395e1a416466c2f5fb9640be8405dc39e
diff --git a/makefiles/release/voltha-versions.mk b/makefiles/release/voltha-versions.mk
new file mode 100644
index 0000000..a6ab7b6
--- /dev/null
+++ b/makefiles/release/voltha-versions.mk
@@ -0,0 +1,44 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+# Intent: Helper makefile target used to setup for a release
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+voltha-versions += master
+voltha-versions += voltha-2.12
+voltha-versions += voltha-2.11
+voltha-versions += voltha-2.8
+voltha-versions += playground
+
+# VOLTHA: release
+#   active : $(words 0,$(voltha-versions))
+#     next : $(words 1,$(voltha-versions))
+#     last : $(words 2,$(voltha-versions))
+
+# fatal to make help (param is null)
+voltha-version ?= $(error $(MAKE) voltha-verison=voltha-x.yy is required)\
+
+voltha-release-this := $(word 1,$(voltha-versions)) 
+voltha-release-last := $(word 2,$(voltha-versions))
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]