Fix suppress_output_file bug where event_callback was not called

[AlanCoding]

Sorry, I had a major flaw with #937 and I should have tested that better before it was merged.

The handle was not passed to pexpect, and that was wrong. The handle is the way that it dispatches events to the event_callback. Even if you do not intend to write to the stdout file, this is necessary.

Design-wise, if suppress_output_file is given, we do want to use the stdout handle wrapper, but we do not want to use the stdout handle itself. I think this code structure articulates that about as best as possible. Alternatively, we could create a null handler and pass that to OutputEventFilter, instead of handling the None case.

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Separately, I may have discovered a bug related to the test failures on the prior PR.

ansible-runner/ansible_runner/utils/__init__.py

Line 373 in d013044

event_data['stdout'] = stdout_chunk[:-2] if len(stdout_chunk) > 2 else ""

This is assuming the .splitlines(True) leaves \r\n at the end of the line. This is... not universal. Because of that, the final character in the echo command gets truncated, because it has a \n without the \r. This looks completely fixable, but I wish to keep that separate.

[AlanCoding]

Here's what the null file-like object looks like:

        class NullWriter:
            def write(self, s):
                pass

            def flush(self):
                pass

            def close(self):
                pass

This is not the implementation here, but it would replace StringIO in the alternative that I discussed. I'm torn as to which is the best.

[ansible-zuul]

LGTM!