parser hangs if using an invalid yaml

[uramirez8707]

Describe the bug
If you have an invalid yaml such as

title:c384L49_esm5PIcontrol
baseDate: 1960 1 1 1 1 1 1
diag_files:
-    fileName: "atmos_daily"
     freq: 24
     frequnit: hours
     timeunit: days
     unlimdim: time

The parser hangs when trying to parse the file.

To Reproduce
Modify any of the parser unit tests to use an invalid yaml and you will see that the code hangs

Expected behavior
The parser should not hang, instead it should produce an error message

This can be done by checking the output to yaml_parser_scan. It will be 0 on error.

System Environment
This happens in any system

Additional context
Thanks @uwagura for bringing this up