[3.6] bpo-33855: Minimally test all IDLE modules. (GH-7689) (GH-7734)

[3.6] bpo-33855: Minimally test all IDLE modules. (GH-7689) (GH-7734)

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..
(cherry picked from commit ee5ef309c7e2daef1248730145408f700732c42e)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>