Provide an operation to distinguish domain & standalone

The console bootstraps form the domain model. It automatically decides to either launch the standalone or domain view. Currently we are checking for a top level "subsystem" element which only exists in standalone mode:

{ [INFO] "operation" => "read-children-names", [INFO] "child-type" => "subsystem", [INFO] "address" => [] [INFO] }

However this operation logs an error on the server side when running the domain mode:

[Host Controller] 15:40:15,052 WARN [org.jboss.as.controller] (HttpManagementService-threads - 9) operation ("read-children-names") failed - address: ([]): org.jboss.as.controller.OperationFailedException
[Host Controller] at org.jboss.as.controller.operations.global.GlobalOperationHandlers$ReadChildrenNamesOperationHandler.execute(GlobalOperationHandlers.java:304)
[Host Controller] at org.jboss.as.domain.controller.operations.ReadChildrenNamesHandler.execute(ReadChildrenNamesHandler.java:65)

In order to cleanup this bootstrap procedure and to remove the server side error, a custom operation to distinguish the two execution modes would be helpful.

i.e.

:get-meta-data()

{
"mode" => "standalone",
"api-version" => "1.0",
"some" => "other value"
}