REST API for pseudowire addition / deletion.

Refactored pseudowire code to use REST in order
to add or delete pseudowires individually. Previous implementation
used the network configuration, which is now completely
removed from the code. Further, I re-organized the code
and create a utility class that holds all the necessary
functionality for verifying pseudowires.

Further, I removed all mastership checks in the pw code
since now a specific pseudowire creation is sent to a single
instance, which will handle the call.

Change-Id: I1eb5e7cc7730ad792ea84dd389475768153e2b68
diff --git a/apps/segmentrouting/web/src/main/resources/definitions/PseudowireDelete.json b/apps/segmentrouting/web/src/main/resources/definitions/PseudowireDelete.json
new file mode 100644
index 0000000..4dd5c04
--- /dev/null
+++ b/apps/segmentrouting/web/src/main/resources/definitions/PseudowireDelete.json
@@ -0,0 +1,14 @@
+{
+  "type": "object",
+  "title": "pseudowire-deletion",
+  "required": [
+    "pwId"
+  ],
+  "properties": {
+    "pwId": {
+      "type": "string",
+      "example": "42",
+      "description": "Id of pseudowire to delete."
+    }
+  }
+}
\ No newline at end of file