Return a normal ordered QuadOperator corresponding to single term.

term A tuple of tuples. The first element of each tuple is an integer indicating the mode on which a boson ladder operator acts, starting from zero. The second element of each tuple is an integer, either 1 or 0, indicating whether creation or annihilation acts on that mode.
coefficient The coefficient of the term. hbar (float): the value of hbar used in the definition of the commutator [q_i, p_j] = i hbar delta_ij. By default hbar=1.

ordered_term (QuadOperator): The normal ordered form of the input. Note that this might have more terms.

In our convention, normal ordering implies terms are ordered from highest tensor factor (on left) to lowest (on right). Also, q operators come first.