Delete uri property when parsing binary_glTF buffer (glTF 1.0)

[lilleyse]

This PR deletes the uri property of the binary_glTF buffer, which is meant to be ignored because the binary chunk should be used instead. Without this fix the glTF 1.0 to 2.0 update step may produce an invalid buffer.

From the KHR_binary_glTF glTF 1.0 extension:

...a runtime can ignore the uri property since the buffer refers to the Binary glTF body section, not an external resource. When a runtime encounters this buffer, it should use the Binary glTF body as the buffer.

Here's what a glTF like this looks like. A fake uri is used because buffer.schema.json requires that uri exists. The uri would be deleted after this change.

  "buffers": {
    "binary_glTF": {
      "type": "arraybuffer",
      "byteLength": 13790,
      "uri": "data:,"
    }
  },

[ptrgags]

@lilleyse what would be the best way to test this? and is there a reason why there aren't any unit tests in this PR?

[lilleyse]

@ptrgags thanks for the reminder, I meant to write a test but forgot

[lilleyse]

@ptrgags ready

[ptrgags]

Looks good, thanks @lilleyse!