Minor fixes

• "devel" and "main" branches do not trigger a pipeline for merge commits.
• Draft Merge requests do not trigger full pipelines.
• Overworked init-script:
  • simulation.yml file added to links.
  • Simplified ConfigFile class interface.
  • Visualization config file added to links also if only animation is used.
• Specifying time step in namelist and not in EXPERIMENT section supported.
• Unnecessary symlink conf/art/jobs.yml deleted.
• Strict checking of correct invocation of ICON in the PREPARE_MEMBER job can be switched off.
• Several minor code fixes that should not have influenced functionality.

Closes #142 .