Add TPC Tracking QA Task

[davidrohr]

@wiechula @stheckel @tklemenz : This adds the standalone TPC QA task to QC (needs AliceO2Group/AliceO2#4846)

• I can get the reconstructed tracks via o2-qc-run-tpctrackreader
• And I am reading the tpc track references from the ROOT file.
  In addition, I would need:
• The track MC labels (can I get them also from o2-qc-run-tpctrackreader somehow).
• The cluster MC labels (I need to cut on how many clusters are found in the TPC to define some findable criterion, and I think for this I need the MC labels). The O2 workflows usually just initialize a RootTreeReader to read tpc clusters + mc labels internally. Is there already a way I can easily provide them for a QC task?

[Barthelemy]

Most of the code is in O2, what I see here is ok.

[Barthelemy]

I wait for @wiechula @stheckel @tklemenz to comment and give approval.

[davidrohr]

The code here is OK, but it canot be used yet. We need:

• Add the components that read track and cluster MC labels.
• Change the nullptrs her to point to the correct MC data.
• Add a json config file to run this task and read data from the new input components.

[Barthelemy]

OK, I propose to "WIP" it then.

[davidrohr]

OK, just wanted to see whether it passes the CI or if I still have to do something, therefore no WIP :)

[tklemenz]

Hi @davidrohr, unfortunately I think I cannot help you much, since we haven't had a look at MC labels, yet.

Concerning the trackreader: If this is the way you want to go instead of taking the data directly from the reco-workflow I think it should be possible to add another output (TPCTracksMCTruth) to the reader. How exactly this would look like I do not know but feel free to modify the reader (QualityControl/Modules/TPC/run/runTPCQCTrackReader.cxx).

Concerning the cluster MC labels: Afaik there is nothing implemented in the QC so far to easily provide MC labels for the clusters. At least not from our side or anyone else that I know of.

[davidrohr]

@tklemenz : Yes, I think we should modify the o2-qc-run-tpctrackreader to provide the mc track labels as a second output.
For the clusters, I guess we should implement an o2-qc-run-tpcclusterreader, which can read and ship the clusters and the cluster mc labels.
In principle, we could even do this inside O2 not inside QC because I think it might be helpful in general to have a device that can provide clusters / tracks as input.
We can discuss this during our call next Wednesday.

[davidrohr]

@Barthelemy : This is now fully working and ready to be merged.