function plot_trace_microsim

[krijkamp]

The function plot_trace_microsim requires the vector with the state names to be called v_names_states
However, this function should not be depending on how this vector is names.
Can we let the v_names_states function read from the data which health states there are, maybe using function unique() and make the vector itself?

Or can we make it an argument of the function that the users have to specify?