[3.15] gh-151678: Add tests for the remaining tkinter Misc, Wm and Text methods ...

[3.15] gh-151678: Add tests for the remaining tkinter Misc, Wm and Text methods (GH-151782) (GH-151799)

Cover Misc.wait_variable and wait_window, tk_focusFollowsMouse,
selection_handle, the error paths of grab_set_global, send, the
X11-specific Wm methods iconposition, iconmask, iconwindow,
colormapwindows and manage/forget, and the Text.window_config alias and
deprecated yview_pickplace.
(cherry picked from commit aa71eb287f6d812e5270109acb9119c2ad0baef9)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>