Simplify how movedata2networkDynamic deals with non-active holdings

[CarlijnB]

By explicitly setting vertex activity spells in the call to networkDynamic, I don't think we need to separate out active/non-active holdings at the start anymore?
especially if we can pass on "incl_nonactive_holdings" argument to holdingids2consecints() for numbering.

Does require testing for equivalent results...

[CarlijnB]

New implementation does not have fully equivalent outputs:

• in the previous implementation, active holdings were first given random identifiers (range 1 to n_active_holdings), and only then non-active holdings were given random identifiers (range n_active_holdings + 1 to n_total holdings).
• in the new implementation, all holdings are given random identifiers at the same time (range 1 to n_total_holdings).