Improve unittest

[nicolargo]

• use PyTest as a default test framework (have a look on official site, migration can be done softly with https://docs.pytest.org/en/8.2.x/how-to/unittest.html)
• Split memory leak test in a specific file
• Create a performance test
• Improve tests by testing all the plugin/model.py methods
• Add dummies tests for all plugins (for example sensors could not be tested in the CI because the CI containers do not expose any sensors)
• Improve Github action unit test on BSD systems #2749

[nicolargo]

Improve tests by testing all the plugin/model.py methods done in Glances 4.0.0

[nicolargo]

Pytest tesbed

Include existing unittest

./venv/bin/pip install pytest

ln -s unittest-core.py test_core.py

./venv/bin/pytest
.....................................                                                                          [100%]
37 passed in 20.43s

Also work with other unitest file:

ln -s unittest-restful.py test_restful.py

ln -s unittest-xmlrpc.py test_xmlrpc.py

./venv/bin/pytest
......................................................................                                         [100%]
70 passed in 31.61s

Add new Pytest tests

Example:

cat /home/nhe/dev/glances/glances/timer_test.py
from .timer import Timer
def test_timer():
    t = Timer(5)
    assert t is not None

./venv/bin/pytest
.                                                                                                              [100%]
1 passed in 0.09s