Options to return WMS Capabilities document without a root Layer tag, when possible
Description
We want to let the admin configure the ability to return WMS capabilities document without the usual root Layer when that is possible, so when there is only one Layer element as its child, for example when asking for a virtual service capabilities for a single layer or layergroup.
The options should be configurable at the service (WMS) level, but also at the Layer / LayerGroup level.
We could also add a vendor parameter to enable this new behaviour per user request.
Environment
None
