A lot of tests in different QUnit modules need this delay to be
patched to 0. Some of them (e.g. the 'ActionManager > Misc' module)
didn't patch it correctly. It worked before because a patch was
done in a previous test, and wasn't unpatch. The previous commit
ensures the patch is removed, so now we have at least 2 tests of
the above mentionned module that fail. This commit ensures that
the delay is patched in every tests, and allows to specify a
custom delay if necessary.