Issue #2473943 by Manjit.Singh, Cottser, mu5a5hi, LewisNyman, mortendk, rteijeiro, rachel_norfolk: Prefix form-file and form-managed-file classes with js-

Issue #2486441 by jibla, richgilbert, entendu, emma.maria, amyvs, mradcliffe, heatherwoz, mu5a5hi, lnicks, hzakaryan: Clean up the "Search results" component in Bartik