bpo-33855: Minimally test all IDLE modules. (GH-7689)

Create a template for minimally testing a tkinter-using module by importing it and instantiating its class(es).  Add a test file for all non-startup IDLE modules.  Edit existing files and update coverage.  This is part 1 of 3, covering the 21 autocomplete to help modules and touching 33 idlelib files.