[3.15] gh-151678: Add tests for tkinter Misc, Wm and geometry manager methods (GH...

[3.15] gh-151678: Add tests for tkinter Misc, Wm and geometry manager methods (GH-151732) (GH-151737)

Cover previously-untested methods of the Misc, Wm, Pack, Place and Grid
classes:

* a new WinfoTest class for the winfo_* query methods (class, name,
  parent, children, toplevel, visual and screen information, atoms,
  pointer and screen coordinates, fpixels, containing, interps,
  viewable), including the pre-existing winfo_rgb and winfo_pathname;
* in MiscTest: getint, getdouble, getvar, register, deletecommand,
  option_add/get/clear, nametowidget, the focus_*, grab_* and
  selection_own* methods, event_add/delete/info, and bell;
* in WmTest: title, geometry, minsize/maxsize, resizable, aspect, grid,
  positionfrom/sizefrom, focusmodel, iconname, client/command,
  overrideredirect, state (with withdraw and deiconify), frame, group,
  protocol and transient;
* the short-named aliases of the grid_*, pack_* and place_* geometry
  manager methods.
(cherry picked from commit 23793ac211371415eaf9491fef031f121969dfb3)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>