GitLab

We do not have a DokuWiki-account. Besides, the used files cannot change.

To group jobs together, this commit adds a stage name to each job. To
facilitate the parallelization of a DAG pipeline in GitLab, this commit
adds the respective inter-job dependencies to each job. This way, most
jobs can be run in parallel.

To make the jobs more aligned with the standard build-test-deploy
pipeline, this commit changes the order of the jobs so that the build
jobs comes first and testing jobs come after the build and before the
deploy jobs.