(foreclosure action against debtor, owner of condominium; state law provides that condominium associations have "a lien on a unit for any unpaid assessments levied against a unit from the time the assessment is due" and lien need not be recorded to be perfected; lien automatically attached at time assessment is due, and statute provides for judicial and non-judicial methods of foreclosing lien; plaintiff's seeking of judicial foreclosure does not negate fact that plaintiff could have pursued non-judicial foreclosure of lien at any time after lien arose; thus, lien was choate and superior to federal tax lien until time federal tax lien recorded).