Merge Integration test files for preprocessing

This MR does the following:

• Fixing indentation in the docker pipeline yaml
• Merging the integration test files of the different preprocessing methods into one.
• Adapting the names of the preprocessing integration tests in the pipeline.
• Removing old unused files (closes #113 (closed))
• Merging the integration test files of the different tagger trainings into one.
• Old integration test files are removed.
• Fixing an old naming issue (Dl1r was called DL1 in some integration tests).
• Adapting pipelines to new files.
• Speeded up the training of dips a bit (closes #107 (closed))