Replace yaml wil saneyml in vulntotal CLI

[ogubuikeAlex]

The vulntotal_cli.py module currently imports and uses the standard yaml library, but there's a TODO comment (line 20) noting that it should be replaced with saneyaml. The project already includes saneyaml as a dependency (version 0.6.0 in requirements.txt) and uses it consistently throughout the codebase in other modules.

The task is

• To replace import yaml with import saneyaml in vulntotal_cli.py,
• Replace yaml.dump() calls with saneyaml.dump()
• Followed by a clean up of the TODO comment
• Running existing test to verify that the YAML output functionality still works

This is important because:

• It would maintain codebase consistency
• sanyaml produces better and more readable yaml formatting
• It will reduce dependency on multiple yaml libraries

cc @TG1999 @ziadhany @pombredanne