Fill datainfo

[olaszsoma]

It is probably needed to fill the datainfo in the output distribution CPO.

[olaszsoma]

Runaway current and density should be saved to CPOs as well.

[olaszsoma]

In the distri_vec, the source of the data should be indicated with a flag in source_id.type.flag part of the CPO. Here, the DISTSOURCE_IDENTIFIER for runaways should be written like in Runaway Fluid.
This is used when an input distribution CPO is given to a code and results from previous runaway calculations have to be found (e.g.).