Bug fixes for ListChangeDrafts and ListChangeComments

[opalmer]

This PR contains two bug fixes. First it updates ListChangeComments to query the correct endpoint (it was changes/<change id>/in).

Second,ListChangeDrafts and ListChangeComments were expecting a response from Gerrit like this:

  {
    "file1": {<comment1>},
    "file2": {<comment2>},
  }

When in fact Gerrit will send this:

  {
    "file1": [{<comment1>}, {<comment2>}],
    "file2": [{<comment3>}, {<comment4>}]
  }

References:

• https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#list-change-comments
• https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#list-change-drafts

[opalmer]

@andygrunwald I checked Gerrit's docs and it appears the API has always responded with a list (or at least it has since 2.11). I guess this just slipped through because nobody has tried using these parts of the API yet heh.

[andygrunwald]

Thank you @opalmer.
I think this part was never used by someone. Thanks for catching this.
Gimme a few more minutes. I will merge it today and fix the tests immediately.

[andygrunwald]

Merged.
Thank you @opalmer

[opalmer]

Anytime, thanks!