Merge branch 'develop' for release 3.12.0-server

.gitlab-ci.yml

.gitlab-ci/docker/Dockerfile-ci

.gitlab-ci/docker/Dockerfile-rpm

.gitlab-ci/docker/docker_push.sh

.gitlab-ci/setup-db.sh

README.md

migration_docs.md

packaging/Dockerfile

packaging/client/fts-rest-client.sh

packaging/client/fts-rest-client.spec

packaging/client/make-dist.sh

packaging/client/make-srpm.sh

packaging/docker/Dockerfile

packaging/docker/docker-compose.yml

packaging/docker/docker-run-example.sh

packaging/server/fts-rest-server.sh

packaging/server/fts-rest-server.spec

packaging/server/make-dist.sh

packaging/server/make-srpm.sh

src/fts3/cli/jobsubmitter.py