Resolve "Generate testing prerelease"

And use new EOLE/infra/ci-tools> templates standards.

The wanted result:

• merging into testing
  • pass the complete pipeline to test everything is fine
  • create the testing prerelease tag
• the testing prerelease tag
  • build the docker image
  • add the :testing docker tag
  • add the :X.Y.Z-testing.1 docker tag
• merging into master
  • pass the complete pipeline to test everything is fine
  • create the new stable release
• the release tag
  • build the docker image
  • add all the tags
  • merge back to dev
• merge-to-dev
  • pass the complete pipeline to test everything is fine
  • build the docker image
  • add the :dev docker tag

Closes #31 (closed)