transcripts do not fail on missing commands

[crotwell]

A non-existant command in a transcript should fail, but it passes even though cmd2 knows that "notacmd is not a recognized command, alias, or macro".

Create a transcript manually:

echo "(Cmd) notacmd" > test_notacmd.txt

Then using first_app example:

python first_app.py --test test_notacmd.txt

output is:

python first_app.py --test test_notacmd.txt
============================= cmd2 transcript test =============================
platform darwin -- Python 3.9.10, cmd2-2.3.3, readline-RlType.GNU
cwd: xxxxx/python-cmd2/cmd2/examples
cmd2 app: first_app.py
collected 1 transcript
notacmd is not a recognized command, alias, or macro
.
----------------------------------------------------------------------
Ran 1 test in 0.003s

OK
===================== 1 transcript passed in 0.003 seconds =====================

[kmvanbrunt]

@crotwell I agree this issue is linked with #1185. We need to decide the best way to capture stderr.
I'm closing this issue so we can track all progress in the other ticket.