Geomap: Rethink standard options for panels with tree structures

Right now some of the standard options for geomap seem to have a geomap that allows for only a single layer in mind (min / max, color schema). This can lead to some limitations / bugs such as https://github.com/grafana/grafana/issues/51185 where the user must manually set the min / max value in standard options for a color scheme marker layer Given geomap supports multiple layers now we may want to rethink how we structure standard options and whether or not some standard options actually make sense more on the layer level vs. global (i.e. to support multiple color schemes per map by layer, layer specific min / max etc.) We should also consider canvas elements in the mix here as well: see [community feedback comment here](https://github.com/grafana/grafana/discussions/56835?sort=new#discussioncomment-4286926)