“Tier-city” means an incorporated community within a consolidated county that (i) has within defined boundaries a population of 5,000 or more, (ii) has been designated as a tier-city by the General Assembly, and (iii) has both the powers of a town and such additional powers as may be granted tier-cities by the General Assembly. All references in this Code and the acts of the General Assembly to towns shall be deemed references to tier-cities, except to the extent tier-cities may be specifically excluded or where the context requires otherwise.