(Corrects paragraph 34 to attribute testimony about Trump throwing a plate to Cassidy Hutchinson, not Kayleigh McEnaney) By Richard Cowan and Moira Warburton WASHINGTON (Reuters) -Donald Trump tried to grab the steering wheel of his presidential limousine on Jan. 6, 2021, when his security detail declined to take him to the U.S. Capitol where his supporters were rioting, a former aide testified on Tuesday. The then-president dismissed concerns that some supporters gathered for his fiery speech outside the White House that day carried AR-15-style rifles, instead asking security to stop screenin…