The District of Columbia has approved the nation's most far-reaching handgun control bill, a measure to make manufacturers and dealers liable for deaths and injuries caused by semiautomatic weapons.  Mayor Marion Barry Jr. said Tuesday that he had signed the bill, which cannot become law until reviewed by Congress.  The Associated Press erroneously reported Monday that the City Council was expected to give final approval on Tuesday. Final passage actually came last week. Congress has 30 days from Jan. 23, when it resumes legislative business, to invalidate the law.