(Un)Register the custom recognize in init() and cleanup() instead of
initTestCase() and cleanupTestCase(), so that a new recognizer is used
for each test function.
In the test functions, use a scope guard to unregister the locally
registered recognizers to make sure that in the case of a failing test
and early return, the recognizer is removed.
Pick-to: 6.5 6.4 6.2
Change-Id: I4fe9509f35474514ef55191d799e6707199fe853
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
58afdea1b3