Enable topLevel InternalProxy for yaml (#2581)

Author: christiangoerdes

core/src/main/java/com/predic8/membrane/core/proxies/InternalProxy.java

@@ -22,7 +22,7 @@
  * <p>Internal proxies are useful to better structure the configuration of the gateway.</p>
  * @topic 1. Proxies and Flow
  */
-@MCElement(name="internal")
+@MCElement(name="internal", topLevel = true, component = false)
 public class InternalProxy extends AbstractServiceProxy implements NotPortOpeningProxy {
 
     public InternalProxy() {

distribution/examples/routing-traffic/content-based-router/apis.yaml

@@ -35,7 +35,7 @@ api:
         status: 200
 
 ---
-api:
+internal:
   name: order
   flow:
     - static:
@@ -44,7 +44,7 @@ api:
         status: 200
 
 ---
-api:
+internal:
   name: express
   flow:
     - static:

distribution/examples/routing-traffic/internalproxy/apis.yaml

@@ -17,7 +17,7 @@ api:
 ---
 # An internal API is like a function or subroutine for an API.
 # For an internal API a port is not needed
-api:
+internal:
   name: express
   flow:
     - static:
@@ -26,7 +26,7 @@ api:
         status: 200
 
 ---
-api:
+internal:
   name: normal
   flow:
     - static: