Create a data table of health state transitions from a transition matrix describing
the states and transitions in a multi-state model suitable for use with hesim_data.
create_trans_dt(trans_mat)A transition matrix in the format from the mstate package.
See IndivCtstmTrans.
Returns a data.table::data.table in tidy format with three columns:
Health state transition ID.
The starting health state.
The health state that will be transitions to.