[ONOS-5897] (vCore) Create Group Manager and Store

Chages.
1. Virtual Group Manager is added
2. Virtual Group Store interface is added
3. Simple Virtual Group Store is added
4. Virtual Group Manager Test cases are added

Change-Id: I6fc1fae99f5b85fd50437b396f57f78e914ad978
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualGroupProviderService.java b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualGroupProviderService.java
index 674bc2e..a6ed87a 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualGroupProviderService.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/virtual/provider/VirtualGroupProviderService.java
@@ -16,7 +16,6 @@
 
 package org.onosproject.incubator.net.virtual.provider;
 
-import org.onosproject.incubator.net.virtual.NetworkId;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupOperation;
@@ -32,29 +31,24 @@
     /**
      * Notifies core if any failure from data plane during group operations.
      *
-     * @param networkId the identity of the virtual network where this rule applies
      * @param deviceId the device ID
      * @param operation offended group operation
      */
-    void groupOperationFailed(NetworkId networkId, DeviceId deviceId,
-                              GroupOperation operation);
+    void groupOperationFailed(DeviceId deviceId, GroupOperation operation);
 
     /**
      * Pushes the collection of group detected in the data plane along
      * with statistics.
      *
-     * @param networkId the identity of the virtual network where this rule applies
      * @param deviceId device identifier
      * @param groupEntries collection of group entries as seen in data plane
      */
-    void pushGroupMetrics(NetworkId networkId,
-                          DeviceId deviceId, Collection<Group> groupEntries);
+    void pushGroupMetrics(DeviceId deviceId, Collection<Group> groupEntries);
 
     /**
      * Notifies store of group failovers.
      *
-     * @param networkId the identity of the virtual network where this rule applies
      * @param failoverGroups failover groups in which a failover has occurred
      */
-    void notifyOfFailovers(NetworkId networkId, Collection<Group> failoverGroups);
+    void notifyOfFailovers(Collection<Group> failoverGroups);
 }