CHICAGO — Gov. J.B. Pritzker, who made banning the sale of assault weapons a key component of his successful reelection campaign this fall, for the first time voiced support for the recently unveiled proposal byIllinois House Democrats that includes outlawing the sale of certain assault-style guns, barring most people under 21 from getting gun permits and banning large-capacity magazines. Pritzker, in his first public comments on the measure since it was filed last week, said he wants the legislation to be passed by the state House and Senate and placed on his desk to be signed into law before…