[CORD-2486] Improve Mcast CLI APIs

It adds following commands:
- sr-mcast-tree which shows the mapping group-tree
- sr-mcast-next which shows the mapping device-next
- mcast-routes which is similar to the unicast command (routes)

It improve following commands:
- mcast-join adds completer and improves output
- mcast-delete adds completer and improves output
- mcast-show improves output and adds completer

Change-Id: I4e273ac23b05142026b6b77317b0c9b7af76c3ec
diff --git a/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index 4f85368..525f84a 100644
--- a/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -105,6 +105,7 @@
 import org.onosproject.segmentrouting.pwaas.DefaultL2TunnelPolicy;
 import org.onosproject.segmentrouting.pwaas.L2TunnelHandler;
 import org.onosproject.segmentrouting.storekey.DestinationSetNextObjectiveStoreKey;
+import org.onosproject.segmentrouting.storekey.McastStoreKey;
 import org.onosproject.segmentrouting.storekey.PortNextObjectiveStoreKey;
 import org.onosproject.segmentrouting.storekey.VlanNextObjectiveStoreKey;
 import org.onosproject.segmentrouting.storekey.XConnectStoreKey;
@@ -662,6 +663,21 @@
         return linkHandler.getDownedPorts();
     }
 
+    @Override
+    public Map<McastStoreKey, Integer> getMcastNextIds(IpAddress mcastIp) {
+        return mcastHandler.getMcastNextIds(mcastIp);
+    }
+
+    @Override
+    public Map<McastStoreKey, McastHandler.McastRole> getMcastRoles(IpAddress mcastIp) {
+        return mcastHandler.getMcastRoles(mcastIp);
+    }
+
+    @Override
+    public Map<ConnectPoint, List<ConnectPoint>> getMcastPaths(IpAddress mcastIp) {
+        return mcastHandler.getMcastPaths(mcastIp);
+    }
+
     /**
      * Extracts the application ID from the manager.
      *