(Corrects first paragraph to clarify the situation heading into the election) By Moira Warburton (Reuters) -Control of the U.S. Senate still had not been determined as of Friday evening, three days after the Nov. 8 midterm elections. Heading into the election, Republicans needed to pick up only one seat to take the majority in the 100-seat chamber, which would allow them to block much of Democratic President Joe Biden’s agenda. The chamber is currently split 50-50 between Republicans and Democrats, who maintain control thanks to Vice President Kamala Harris’ tie-breaking vote. Democrats hope t…