It creates the UECM (Unrestricted Error Correction Model) specification according to the given "formula" and the corresponding "order" of the underlying ARDL.
build_uecm_formula(parsed_formula, order)A list containing the formula parts as returned from
parse_formula.
A numeric vector with the underlying ARDL order as returned from
parse_order(restriction = FALSE).
build_uecm_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.