Added ui-cache-regions CLI command.

Change-Id: I196543792c85e40e582f9456e4e50dd33bedf111
diff --git a/web/gui/src/main/java/org/onosproject/ui/impl/topo/model/ModelCache.java b/web/gui/src/main/java/org/onosproject/ui/impl/topo/model/ModelCache.java
index 8647c59..e3fedd1 100644
--- a/web/gui/src/main/java/org/onosproject/ui/impl/topo/model/ModelCache.java
+++ b/web/gui/src/main/java/org/onosproject/ui/impl/topo/model/ModelCache.java
@@ -240,6 +240,10 @@
         }
     }
 
+    Set<UiRegion> getAllRegions() {
+        return uiTopology.allRegions();
+    }
+
 
     // === DEVICES