[3.14] gh-65784: Add support for parametrized resource wantobjects in regrtests (GH-143570) (GH-143913)

This allows to run Tkinter tests with the specified value of
tkinter.wantobjects, for example "-u wantobjects=0".
(cherry picked from commit 21ed1e2a9401a2e96ccc910fcb66f22afc96efbd)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>