Disable completion/ElDoc/FFAP when Python program is running

Disable completion/ElDoc/FFAP when Python program is running

* lisp/progmodes/python.el (python-completion-at-point)
(python-ffap-module-path, python-eldoc--get-doc-at-point): Add check
using `python-util-comint-end-of-output-p'.
(python-util-comint-end-of-output-p): New function.
* test/lisp/progmodes/python-tests.el (python-tests-shell-wait-for-prompt):
Use `python-util-comint-end-of-output-p'.
(python-completion-at-point-while-running-1)
(python-ffap-module-path-1)
(python-ffap-module-path-while-running-1)
(python-eldoc--get-doc-at-point-1)
(python-eldoc--get-doc-at-point-while-running-1): New tests.
(Bug#58713)