Are there any plans to support 3D center points with height in the 3D map?

Nobody has claimed this yet.

## Motivation

Hello, do you have any plans to enable support for 3D center points in the map? For example, setting the center of the map as center: [lng, lat, height], supporting height. It would be great if the camera's viewpoint with height could be maintained when rotating or zooming the map.

## example
```
var map = window.map = new mapboxgl.Map({
center: [-122.4194, 37.7749, height: number],
});
```

The scenario is: For example, there is a model on top of a building, 100 meters above the ground. I would like to rotate and zoom the map around this model.

No files, tests, or entry points are named. Start by tracing the map center and camera APIs and how 3D viewpoints are handled. Done would mean accepting a center with longitude, latitude, and height, then preserving that elevated viewpoint while rotating or zooming.

Written by the indexing model from the issue text.