Increase the quality of the automated regression tests

[amilcarlucas]

Is there an existing issue or pull request for this?

• I have searched the existing issues and pull requests

Feature description

The tests have BDD documentation, are quite extensive and have a 97% code coverage: https://coveralls.io/github/ArduPilot/MethodicConfigurator
Their structure is documented in the pytest_testing_instructions.md file.
https://github.com/ArduPilot/MethodicConfigurator/blob/master/.github/instructions/pytest_testing_instructions.md

Desired solution

It would be good to improve them and extend them even more.
The only file that should not be improved is the frontend_tkinter_parameter_editor_table.py and related test files, because I plan to refactor that file in the future

Alternatives considered

None

Additional context

No response

[amilcarlucas]

fixed by #1638 and #1639