Support other streams and read transform args in TLA decoding
FYI @mmontell.
Running Reco_tf.py --outputDAOD_TLAFile=[blah] --maxEvents 10
for example was ignoring the event count limit because the transform arguments were not being parsed. This adds the common and reco arg parsing.
For future compatibility, add an argument to the TLA decoding function so that other streams can be decoded as well. This might even need to be a list, but can be finalised when a concrete use case is properly implemented.