Honor the resolved/unresolved state of pull request comments #2245

At the moment pull request comments are only hidden inside the extension when the code near to them hasn't been changed (they're not marked as Outdated on github.com). The option to Resolve conversation has recently been added to github.com. We should continue showing conversations until they have been marked as resolved.

How it looks on dotcom

Here is a comment on the github.com conversation view that is marked as Outdated but that is still visible because it hasn't been resolved.

Here is a comment that is visible on the diff view that isn't Outdated, but that has been resolved.

Required APIs

Unfortunately the GraphQL schema that exposes the resolved/unresolved state of comments is under preview.

• https://developer.github.com/changes/2018-10-24-more-complete-pulls-workflow-in-graphql/
• https://developer.github.com/changes/2018-08-29-resolvable-threads/
• https://developer.github.com/v4/previews/#pull-requests-preview
• https://developer.github.com/v4/previews/#resolvable-threads-preview

In order to use use these preview schema together, the API needs to be accessed using the following header:

Accept: application/vnd.github.ocelot-preview;application/vnd.github.cateye-preview+json

This isn't supported by GitHub's API explorer but is supported by the GraphiQL app.

You will need to use a GraphQL endpoint of:

https://api.github.com/graphql?access_token=your_personal_access_token

Here is a sample query:

{
  repository(owner: "github", name: "VisualStudio")
  {
    pullRequest(number: 2241)
    {
      reviewThreads(first: 100)
      {
        nodes        
        {    
          isResolved resolvedBy { name }
          
          comments(first: 100)
          {
            nodes { path bodyText }
          }
        }
      }
    }
  }
}

Here is a resolved comment thread:

            {
              "isResolved": true,
              "resolvedBy": {
                "name": "Jamie Cansdale"
              },
              "comments": {
                "nodes": [
                  {
                    "path": "src/GitHub.App/Services/RepositoryCloneService.cs",
                    "bodyText": "Maybe we should move the log.Error(...) to above DeleteDirectory in case it also throws?"
                  }
                ]
              }
            }