Issue #1201 capture output example tests

[JoerivanEngelen]

Fixes #1201

Description

Print stderr and stdout message when example in test_examples.py fails.

It will print a message like:

    @pytest.mark.parametrize("example", get_examples())
    def test_example(example):
        result = subprocess.run([sys.executable, example], capture_output=True)
        if result.returncode != 0:
>           raise RuntimeError(
                f"Example failed to run with returncode: {result.returncode} \n\n"
                f"stdout: {result.stdout.decode()} \n\n"
                f"stderr: {result.stderr.decode()} \n\n"
            )
E           RuntimeError: Example failed to run with returncode: 1 
E           
E           stdout:  
E           
E           stderr: Unzipping contents of 'C:\Users\Herman\AppData\Local\imod\imod\Cache\hondsrug-simulation.zip' to 'C:\Users\Herman\AppData\Local\Temp\tmpkhwjabqu\hondsrug_saved'
E           Traceback (most recent call last):
E             File "c:\src\imod-python\examples\mf6\hondsrug_partitioning.py", line 52, in <module>
E               raise ValueError("Some failure")
E           ValueError: Some failure

Checklist

• Links to correct issue
• Update changelog, if changes affect users
• PR title starts with Issue #nr, e.g. Issue #737
• Unit tests were added
• If feature added: Added/extended example

[sonarqubecloud]

Quality Gate failed

Failed conditions
C Reliability Rating on New Code (required ≥ A)

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