Fix Direct Dependencies Marked as Indirect

[ljones140]

There is a bug where components have themselves in top level referrers they mark themselves as indirect.

Extracted the component to snapshot manifest transformation and added tests for different permutations of direct and indirect dependencies.

If we look at this component returned by component detection we can see that it has itself in the top level referrers.
That was causing the previous implementation to mark it as indirect incorrectly.

    {
      "locationsFoundAt": [
        "/requirements.txt"
      ],
      "component": {
        "name": "h11",
        "version": "0.16.0",
        "author": "Nathaniel J. Smith",
        "license": "MIT",
        "type": "Pip",
        "packageUrl": {
          "Scheme": "pkg",
          "Type": "pypi",
          "Namespace": null,
          "Name": "h11",
          "Version": "0.16.0",
          "Qualifiers": null,
          "Subpath": null
        },
        "id": "h11 0.16.0 - pip"
      },
      "detectorId": "PipReport",
      "isDevelopmentDependency": null,
      "dependencyScope": null,
      "topLevelReferrers": [
        {
          "name": "httpcore",
          "version": "1.0.9",
          "author": "Tom Christie <[email protected]>",
          "license": "BSD License",
          "type": "Pip",
          "packageUrl": {
            "Scheme": "pkg",
            "Type": "pypi",
            "Namespace": null,
            "Name": "httpcore",
            "Version": "1.0.9",
            "Qualifiers": null,
            "Subpath": null
          },
          "id": "httpcore 1.0.9 - pip"
        }
      ],

Closes: https://github.com/github/dependency-graph/issues/6467

[juxtin]

Looks good!