More informative output for failed CLI tests in CI

[cameel]

Currently cmdlineTests.sh compares the exit codes first, then stdout, and only last stderr. This makes CI output quite confusing, e.g. from t_osx_cli (1677888):

 - strict_asm_debug_info_print_none
 - strict_asm_debug_info_print_snippet_only
 - strict_asm_eof_container_prague
Incorrect exit code. Expected 0 but got 1.

Traceback (most recent call last):
  File "/Users/distiller/project/.circleci/parallel_cli_tests.py", line 40, in <module>
    subprocess.run(
  File "/Users/distiller/.pyenv/versions/3.11.5/lib/python3.11/subprocess.py", line 571, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['test/cmdlineTests.sh', '--exclude', '~ast_export_with_stop_after_parsing', '--exclude', '~soljson_via_fuzzer', '--exclude', '~compilation_tests', '--exclude', '~ast_import_export', '--exclude', '~documentation_examples', '--exclude', '~via_ir_equivalence', '--exclude', '~evmasm_import_export']' returned non-zero exit status 1.

Exited with code exit status 1

Incorrect exit code. Expected 0 but got 1. actually refers to compiler's exit code but it's not very clear here. And then we don't see what the error is.

The PR fixes this by comparing stderr first, which will always show the errors if there are any. Exit code is compared last, because it's the least informative.

The PR also makes parallel_cli_tests.py gracefully handle test failures. It now displays a short message instead of the whole stack trace.

[cameel]

Note that while the diff may at first look like there are more changes here, I'm really only changing the order of the ifs.

[r0qs]

Nice. Looks good to me.

[clonker]

I didn't know you could exit with an object instead of an integer code. Neat.

[cameel]

I actually didn't know that myself. I forgot a string conversion here at first, then realized it still works :)

But I did know that you can pass in a string and it makes it exit with code 1 and print the message to stderr, which is a nice shortcut.