[VOL-4055][ONOS-8138] Adding annotations to meter to allow passing of associated information

This patch allows for adding key value elements in the meter request and in the meter generated from it.
An example is:
Annotations annotations = DefaultAnnotations.builder().set("MeterForDeviceType", "olt").build();
DefaultMeterRequest.builder().withAnnotations(annotations)
Generates:
 DefaultMeter{device=of:00000a0a0a0a0a0b, cellId=2, appId=org.opencord.olt, unit=KB_PER_SEC, isBurst=true, state=ADDED, bands=[DefaultBand{rate=100000, burst-size=5000, type=DROP, drop-precedence=null}, DefaultBand{rate=100000, burst-size=5000, type=DROP, drop-precedence=null}, DefaultBand{rate=100000, burst-size=0, type=DROP, drop-precedence=null}], annotations={MeterForDeviceType=olt}}

Change-Id: Ifaded96ebeb7956bc60cdf311180c984c3ba954e
diff --git a/core/api/src/main/java/org/onosproject/net/meter/Meter.java b/core/api/src/main/java/org/onosproject/net/meter/Meter.java
index 3d7544e..63b6db3 100644
--- a/core/api/src/main/java/org/onosproject/net/meter/Meter.java
+++ b/core/api/src/main/java/org/onosproject/net/meter/Meter.java
@@ -16,6 +16,8 @@
 package org.onosproject.net.meter;
 
 import org.onosproject.core.ApplicationId;
+import org.onosproject.net.Annotated;
+import org.onosproject.net.Annotations;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.pi.service.PiTranslatable;
 
@@ -24,7 +26,7 @@
 /**
  * Represents a generalized meter cell configuration to be deployed on a device.
  */
-public interface Meter extends PiTranslatable {
+public interface Meter extends PiTranslatable, Annotated {
 
     enum Unit {
         /**
@@ -190,6 +192,14 @@
         Builder withBands(Collection<Band> bands);
 
         /**
+         * Sets the annotations.
+         *
+         * @param annotations annotations
+         * @return builder object
+         */
+        Builder withAnnotations(Annotations annotations);
+
+        /**
          * Builds the meter based on the specified parameters.
          *
          * @return a meter