[3.12] gh-111942: Fix crashes in TextIOWrapper.reconfigure() (GH-111976) (GH-112058)

* Fix crash when encoding is not string or None.
* Fix crash when both line_buffering and write_through raise exception
  when converted ti int.
* Add a number of tests for constructor and reconfigure() method
  with invalid arguments.

(cherry picked from commit ee06fffd38cb51ce1c045da9d8336d9ce13c318a)

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