SOL003 VNF Indicator - Implementation of deltas between v3.3.1 and v2.7.1

This merge request refers to the implementation of deltas between v3.3.1 and v2.7.1 of SOL003 VNF Indicator Interface.

@lynchpi @aelken @matsuurat @carignani @sayama @kraja @zulfiqar @zafar

Deadline for review: Friday 12th March 2021 @6pm CET

Review period elapsed: approved !

SOL003/VNFIndicator-API/jsons/SupportedIndicatorsChangeNotification.json

+{{
+	"id":"",
+	"notificationType":"SupportedIndicatorsChangeNotification",
+	"subscriptionId":"{subscriptionId}",
+	"timeStamp":"",
+	"vnfInstanceId":"{vnfInstanceId}",
+	"supportedIndicators":{{
+		"vnfIndicatorId":"{indicatorId}"
+	}}
+	"_links":{{
+		"vnfInstance":"",
+		"subscription":""
+	}}
+}}
\ No newline at end of file