The map-controls 3D button works on every style

map-controls' terrain button now lifts any of the fifteen styles, base included, through the gateway's terrain=on, and the map item takes terrain and exaggeration props. Turned on in unmap Maps, Trail Explorer, the elevation explorer block and the elevation profile example.

• <MapControls terrain /> (Vue: <UnmapMapControls terrain />) shows its 3D button on every style. A style with its own elevation (outdoor, atlas, swiss, winter) lifts in place, as before; any other reloads with terrain=on
• <Map terrain exaggeration={1.5} /> (Vue: <UnmapMap terrain :exaggeration="1.5" />) starts a map on 3D terrain, and map-context's useMapTerrain() lets your own control ask for it
• unmap Maps and Trail Explorer have the 3D button, and so do the elevation explorer block and the elevation profile example