Tile transforms performance hit

[jjhembd]

When rendering camera flights through a detailed 3D Tileset, frame rate can suffer, with much of the CPU time taken up by tile transforms. This problem was partially addressed in #11211, but it can still be an issue in full-screen views.

See this Sandcastle of a detailed photogrammetry tileset, and click the fullscreen button in the bottom right of the Viewer.

Performance profiles are dominated by functions like Matrix4.multiplyTransformation, Matrix3.getColumn, and OrientedBoundingBox.distanceSquaredTo, most of which are being called from Cesium3DTile.prototype.updateVisibility.

Cesium3DTile.prototype.updateVisibility is called for every tile in the scene, every pass of every frame. It should be sufficient to do the matrix work only once per tile per frame, and re-use the results for different passes.