[QC-602] Batch processing in QC

[knopers8]

This allows to process partial data by QC Tasks and dump/merge results into a file.
Then, the merged results can be picked up by the last parts of the QC chain (Checks, Aggregators, storage).

[knopers8]

@Barthelemy This is essentially working and ready for a review, I only have to write tests now.
I am especially not sure about the naming, so any other suggestions for "local batch", "remote batch", "RootFileSink" and "RootFileSource" will be very welcome.

[Barthelemy]

I'll review it today.

[knopers8]

I am not sure it is related to tuning the test parameters #777
but three tests now failed in o2-dataflow:

## sw/BUILD/QualityControl-latest/log
--
 5/48 Test #38: testFactory .............................***Timeout  20.97 sec
--
 9/48 Test #16: testCcdbDatabase ........................***Timeout  30.37 sec
--
36/48 Test #32: multinode_test ..........................***Failed   42.98 sec
--
94% tests passed, 3 tests failed out of 48

[Barthelemy]

Weird. I did not touch testCheckWorkflow which is the only one I see actually failing.

The following tests FAILED:
	 25 - testCheckWorkflow (Timeout)
Errors while running CTest

I will also increase the timeout for testCheckWorkflow

[Barthelemy]

Good, the naming is ok, I don't have a better proposal.

The infrastructure generator is what it is ... :)

I tried to run the test but I get:

Error, monitor object of the QC Task could not be found.

[knopers8]

The test could fail this way if you provide it with wrong UNIQUE_ID env var. It passes CI now, so I doubt this is a real problem.