Add example test for a complex sequence validation

Adds a new sequence running both the restricted (default) and non-restricted veloUT tracking and also two instances of the forward tracking: one with restricted veloUT tracks as input and one with non-restricted veloUT tracks as input. Validation algorithms for track reconstruction efficiencies are run on all instances of the track reconstruction algorithms. A CI test is added for this "complex" sequence.

Modifications done in the context of this work:

• Merge the MC validation inside sequence branch with the multi-event-scheduler branch, make it work for the default case
• Create validators.py with functions to call the various validation algorithms, the reconstructed objects to be validated are passed as arguments
• Remove **kwargs from all function calls of the python configuration, make dependencies explicit
• Rename files in configuration/sequences/definitions, since they no longer define "sequences", but rather call parts of the reconstruction or selection lines
• Rename some of the "sequence" files in configuration/sequences to reflect the algorithms they run
• reference files for physics efficiency tests now also contain the sequence name
• split HLT1.py (in configuration/sequences/) into hlt1_reconstruction.py, persistency.py, hlt1_alignment_lines.py, hlt1_charm_lines.py, hlt1_inclusive_hadron_lines.py, hlt1_muon_lines.py, hlt1_technical_lines.py
• Created a corresponding directory hierarchy inside device/selections/lines, i.e. creating alignment, charm, inclusive_hadron, muon, technical

to do:

• Add CI test for the newly added "complex" sequence

Lessons learnt:

There seems to be an upper limit on the number of characters allowed for a JOB_NAME in the .gitlab-ci.yml file. The newly added test only worked when giving the sequence a short name.

Depends on !522 (merged)