Add default HLT2 input split by file type
In !673 (merged) the ambiguity of "default inputs" for our tests led to to discussion - probably more than needed ;-). Like with the already existing MDF input, it would be good to have input files explicitly split by file type:
- LDST
- DST
- XDIGI / xdst
This allows us to make the requirement for out options file quite explicit in the "example" qmt files. For the current tracking studies, the all-containing xdigi format is considered the default, but later also some MC studies have to be performed using DST files.