SOL002 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 SOL002 VNF LCM Interface.

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

**Deadline for review: Wednesday 3rd March 2021 @6pm CET

Review period elapsed: approved**

SOL002/VNFLifecycleManagement-API/IndividualVNFSnapshot.robot

@@ -53,15 +53,15 @@ PUT Individual VNF Snapshot - Method not implemented
     PUT individual VNF Snapshot
     Check HTTP Response Status Code Is    405
 
-PATCH Individual VNF Snapshot - Method Not Allowed
+PATCH Individual VNF Snapshot - Method not implemented
     [Documentation]    Test ID: 6.3.5.26.5
-    ...    Test title: PATCH Individual VNF Snapshot
-    ...    Test objective: This method modifies an individual VNF Snapshot resource
+    ...    Test title: PATCH Individual VNF Snapshot - Method not implemented
+    ...    Test objective: The objective is to test that PATCH method is not implemented
     ...    Pre-conditions: none
     ...    Reference: Clause 5.4.24.3.4 - ETSI GS NFV-SOL 002 [2] v3.3.1
     ...    Config ID: Config_prod_VE
     ...    Applicability: none
-    ...    Post-Conditions: VNF Snapshot modified
+    ...    Post-Conditions: none
     PATCH individual VNF Snapshot
     Check HTTP Response Status Code Is    405