[ODTN] Add read/create/delete ConnectivityService RPC

- RPC: get service interface point
- RPC: get connectivity service list
- RPC: get connectivity service detail
- RPC: create connectivity service
- RPC: delete connectivity service

- Filter method of TAPI resolver for both Node / NEP
- Change condition for sip to odtn-port-type
- Use odtn-port-type in path-computation mock
- Create CEP at topology discovery

- Add sample path calculator
- Add connection-id based path selection

Change-Id: I2f08aacb3dd14b6b3c59a64a349e50abb495f70b
diff --git a/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiNepPair.java b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiNepPair.java
new file mode 100644
index 0000000..a442586
--- /dev/null
+++ b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiNepPair.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.odtn.utils.tapi;
+
+import java.util.Objects;
+import java.util.stream.Stream;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * TAPI NepRef pair class for representation of endpoints of single connection.
+ */
+public class TapiNepPair {
+
+    private TapiNepRef left;
+    private TapiNepRef right;
+
+    public TapiNepPair() {
+    }
+
+    public static TapiNepPair create(TapiNepRef left, TapiNepRef right) {
+        TapiNepPair self = new TapiNepPair();
+        self.left = left;
+        self.right = right;
+        return self;
+    }
+
+    public TapiNepRef left() {
+        return left;
+    }
+
+    public TapiNepRef right() {
+        return right;
+    }
+
+    public TapiNepPair invert() {
+        return TapiNepPair.create(right, left);
+    }
+
+    public boolean isSameNode() {
+        return left.getTopologyId().equals(right.getTopologyId()) && left.getNodeId().equals(right.getNodeId());
+    }
+
+    public Stream<TapiNepRef> stream() {
+        return Stream.of(left, right);
+    }
+
+    public String toString() {
+        return toStringHelper(getClass())
+                .add("left", left)
+                .add("right", right)
+                .toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof TapiNepPair)) {
+            return false;
+        }
+        TapiNepPair that = (TapiNepPair) o;
+        return Objects.equals(left, that.left) &&
+                Objects.equals(right, that.right);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(left, right);
+    }
+}