Replace js-yaml with yaml

[remcohaszing]

What does this PR do?

In #442 yaml-language-server-parser is being replaced with yaml for parsing the AST. yaml can also replace js-yaml for parsing YAML in other places. This saves a dependency.

What issues does this PR fix or reference?

N/A

Is it tested? How?

Existing unittests didn’t break.

[coveralls]

Coverage increased (+0.1%) to 78.492% when pulling 0c3ee7a on remcohaszing:replace-js-yaml into 4819456 on redhat-developer:main.

[evidolob]

@remcohaszing Could you update package.json with main?

[remcohaszing]

Done 😄