Section twenty three of chapter one hundred and twenty-one B, titled “Housing And Urban Renewal,” authorizes a municipality to do “any and all … things necessary or convenient to aid and cooperate in the planning, construction or operation of a housing, clearance, relocation or urban renewal project within its limits.” Such things include the adoption or modification of its zoning rules and regulations, the purchase of any of the bonds or notes of an operating agency and the selling, conveyance or leasing of any of its interests in any property to such agency. The chapter further grants diverse and broad authority to municipalities and their Urban Renewal Housing Authorities, Regional Housing Authorities, or Redevelopment authorities, collectively called urban renewal agencies or operating agencies, in the undertaking of urban redevelopment and affordable housing projects, etc.