SOL003 VNF Lifecycle Management - 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 Lifecycle Management Interface.

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

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

Review period elapsed: approved !

SOL003/VNFLifecycleManagement-API/IndividualVNFSnapshot.robot

@@ -31,9 +31,9 @@ GET Information about an individual VNF Snapshot - NOT FOUND
      [Documentation]    Test ID: 7.3.1.41.3
     ...    Test title: GET Information about an individual VNF Snapshot - NOT FOUND
     ...    Test objective: The objective is to test that the retrieval of individual VNF Snapshot fails when using an invalid resource identifier.
-    ...    Pre-conditions: At least one individual VNF Snapshot is available in the NFV-MANO.
+    ...    Pre-conditions: none
     ...    Reference: Clause 5.4.24.3.2 - ETSI GS NFV-SOL 003 [1] v3.3.1
-    ...    Config ID: Config_prod_NFV-MANO
+    ...    Config ID: Config_prod_VNFM
     ...    Applicability: none
     ...    Post-Conditions: none
     GET Individual VNF Snapshot with Invalid URI