Review orange-qt test utilities to re-use silx test utilities

[woutdenolf]

silx-kit/silx#4624 (comment)

1. The Qt Application (there can be only one for the entire session):

   ewoksorange/src/ewoksorange/tests/conftest.py

   Line 67 in 31eb80c

   def qtapp():

2. The Orange canvas:

   ewoksorange/src/ewoksorange/tests/conftest.py

   Line 81 in 31eb80c

   def raw_ewoks_orange_canvas(qtapp):

3. Execute Ewoks task (using the widget or the core Task):

   ewoksorange/src/ewoksorange/tests/utils.py

   Line 15 in 31eb80c

   def execute_task(

[woutdenolf]

Usage of the ewoksorange test utilities should be improved in the apps

https://gitlab.esrf.fr/workflow/ewoksapps/ewoksfluo/-/blob/main/src/ewoksfluo/tests/conftest.py?ref_type=heads#L5

A pytest plugin would be useful. See for example

https://gitlab.esrf.fr/workflow/pyslurmutils/-/tree/main/src?ref_type=heads

[woutdenolf]

There is also pytest-qt.

silx-kit/silx#4624 (comment)