Optimize CI build_and_push jobs

Reviewers: @bwrona @kmochocki

Previously all images were pushed to the:

• https://gitlab.syncad.com/hive/clive/container_registry/518
• https://gitlab.syncad.com/hive/clive/container_registry/506

repositories. This had 2 problems:

• a lot of images being pushed (with every git push command due to automatic build_and_push` process), so this is a waste of space and time of our servers
• it was hard to distinguish stable images from other images

2 things were changed to the CI docker image build and push process:

• on feature branches, build_and_push jobs are not run automatically, but with manual action.
• stable (master, develop) images are pushed to a separate container registry "directory" to make it easier to distinguish them from other images