sticky source min/maxzoom

[andrewharvey]

I find myself loading up a vector mbtiles then turning the tab to offline so I can overzoom to more easily see how geometries are being stored a specific zoom level.

A stick source min/maxzoom feature would make this a bit easier.

It looks like you can't change a source maxzoom once added to the map, so would need to manage removing and re-adding the source.