totalVertexCount seems misleading, based on accessors rather than on buffers

[tim-rex]

Perhaps this is by design, but it seems that the reported totalVertexCount field is perhaps misleading...

For instance, the Brainstem.gltf model reports as follows:

        "animationCount": 1,
        "materialCount": 59,
        "hasMorphTargets": false,
        "hasSkins": true,
        "hasTextures": false,
        "hasDefaultScene": true,
        "drawCallCount": 59,
        "totalVertexCount": 34159,
        "totalTriangleCount": 61666,
        "maxUVs": 0,
        "maxInfluences": 4,
        "maxAttributes": 4

Whereas the same model that has been processed using third-party tooling (which happens to make more liberal use of accessors and bufferViews) reports:

        "animationCount": 1,
        "materialCount": 59,
        "hasMorphTargets": false,
        "hasSkins": true,
        "hasTextures": false,
        "hasDefaultScene": true,
        "drawCallCount": 59,
        "totalVertexCount": 1047958,
        "totalTriangleCount": 30832,
        "maxUVs": 0,
        "maxInfluences": 4,
        "maxAttributes": 4

Note the totalVertexCount is disproportionately large, when in actual fact the single buffer that is referenced is some 30% smaller in the second example.

I guess it is double counting where accessors are referencing the same bufferView.