It creates the ARDL specification according to the given "formula" and their corresponding "orders".
build_ardl_formula(parsed_formula, order)build_ardl_formula returns a list containing the full formula
and the independent and dependent parts of the formula separated. The full
formula is ready to be used as input in the dynlm function.
A list containing the formula parts as returned from
parse_formula.
A numeric vector with the ARDL order as returned from
parse_order(restriction = FALSE).
Kleanthis Natsiopoulos, klnatsio@gmail.com
build_uecm_formula, build_recm_formula