Replace manual parsing of head comments

[SgtCoDFish]

This leaves more to the YAML parser so we have less chance of accidentally introducing a bug or security issue in our own logic.

Also adds preservation of footer comments as a bonus!

In addition, this fixes klone init and klone add which are currently broken on main when run in a directory with no klone.yaml. That bug was caused by the comment preservation logic!

[inteon]

@SgtCoDFish
#4 added the necessary tests that will make sure this PR is tested for some of the yaml weirdness that can happen.

[SgtCoDFish]

It seems like the "weirdness" is that there's a difference between the following:

# Comment

targets:
  target1:
    - ...

On the above, the comment is on the "document" and this PR will preserve it.

# Comment
targets:
  target1:
    - ...

On this one, the coment is on the targets node and this PR (as initially written) doesn't preserve it. The comment is in rawDocument.Content[0].Content[0].HeadComment and not rawDocument.HeadComment

[jetstack-bot]

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[SgtCoDFish]

The latest commit passes the tests by adding a newline to the test cases so that the comments are now doc comments. I dunno about this... it makes sense to only preserve doc comments to me, and I can see why the yaml parser would treat the other comments differently. I'm not militant about it though

[SgtCoDFish]

I think it'd be better to use a YAML parser for this but I don't think it's worth the effort coming up with a better solution here. Closing.

[inteon]

I think it'd be better to use a YAML parser for this but I don't think it's worth the effort coming up with a better solution here. Closing.

Thanks for testing and letting me know about the io.EOF error btw!