3D: Error first time loading glb model/vector tile datasource

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I observe the following error on first time loading https://bertt.github.io/mapbox_3dtiles_samples/samples/standard/trees/#15.97/52.089726/5.126581/0/58 , no trees are drawn.

In this site a glTF model (tree.glb) is visualized using vector tiles datasource.

```
Uncaught TypeError: Failed to construct 'Request': Failed to parse URL from tiles/14/8423/5404.pbf
at 06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:1:10799
at we (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:1:12630)
at Ee (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:1:13534)
at 06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:286706
at Yb.request (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:286208)
at e.VectorTileWorkerSource.Kb [as loadVectorData] (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:286620)
at e.VectorTileWorkerSource.loadTile (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:821505)
at V.loadTile (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:852309)
at Lb.processTask (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:271083)
at cancelCallbacks..scheduler.add.e.metadata.type (06b1c777-7526-4e7e-ad6c-7f98b3e4bf92:3:270591)
```

After reload the trees from vector tiles are drawn with tree.glb model.


This sample is using v3.0.0-beta.1

Reproduce the linked 3D sample with the vector tiles datasource and tree.glb model, focusing on the first-load request path that produces the relative tiles/14/8423/5404.pbf URL. Compare the initial load with a reload, then verify that the sample draws the trees on first load without the Request URL parsing error.

Written by the indexing model from the issue text.