Certain GUI views are eating up performance

[cohaereo]

The inspector eats up about 5ms of frametime

The About menu is by far the worst, presumably due to my crappy implementation of the egui image loader

[Froggy618157725]

For inspector, it is specifically static instance, not static instances. Terrain is also fine.

[cohaereo]

The cause of the performance hit in the inspector was caused by the continuous polling of the distance from the camera to the fragment under the crosshair, as this was pulling depth buffer data synchronously each frame, causing significant slowdowns.

The polling behaviour has been removed since c863cf5, may be reimplemented in the future with a better distance testing solution