Former Gov. Charlie Crist, long expected to run for St. Petersburg Mayor, has officially filed for the race. Crist filed to run Monday, setting up a competitive challenge to incumbent Mayor Ken Welch. A host of other candidates, who so far have significantly less cash on hand and have lower name recognition than the former Governor, are running as well. “St. Pete has always been a city on the rise,” Crist told the Tampa Bay Times, who broke news…