There have been dozens of TV moms over the years, so who is America's favorite?   The Harris Poll has conducted a survey, and June Cleaver of the series Leave It To Beaver was named the TV mom we would most like to have had growing up.   Claire Huxtable of The Cosby Show was ranked second, followed by Carol Brady of The Brady Bunch.   Marion Cunningham from Happy Days and Donna Stone from The Donna Reed Show were tied for fourth.   Also appearing on the list of favorite TV moms were Lucy Ricardo from I Love Lucy and Samantha Stevens from Bewitched.