Include map config adapters into create-layergroup-map-config-provider

[dgaubert]

Include map config adapters into create-layergroup-map-config-provider instead of using a separate middleware. Thus, we can follow the same workflow that we have for named maps.

Also, we can do the same with context and limits.

Then we can rename create-layergroup-map-config-provider -> anonymous-map-config-provider