Remove the reader from the PodioDataSvc and make the PodioInput populate the internal Frame

[tmadlener]

Currently, the PodioDataSvc holds a ROOTFrameReader which is used for configuring the input file. On the other hand the collections that should be read are configured via the PodioInput algorithm. All of the input configuration should live in the PodioInput.

Other points to address:

• Currently all collections have to be stated in the options file. This should become optional to restrict the collections with a default of reading all collections if not stated otherwise.

Food for thought: Could we simply take the default DataHandle from Gaudi and populate it in PodioInput (from the Frame we read there) and take things out again in PodioOutput (put it into a Frame and write things out). Could potentially solve the issues we observe with k4Gen.