Add NS and VNF package to test support of several volumes

Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

several_volumes_ns/several_volumes_nsd.yaml

+nsd:
+  nsd:
+  - description: NS with 1 VNFs connected to mgmtnet VL
+    df:
+    - id: default-df
+      vnf-profile:
+      - id: vnf-several-volumes
+        virtual-link-connectivity:
+        - constituent-cpd-id:
+          - constituent-base-element-id: vnf-several-volumes
+            constituent-cpd-id: vnf-mgmt-ext
+          virtual-link-profile-id: mgmtnet
+        vnfd-id: several_volumes-vnf
+    id: several_volumes-ns
+    name: several_volumes-ns
+    version: '1.0'
+    virtual-link-desc:
+    - id: mgmtnet
+      mgmt-network: true
+    vnfd-id:
+    - several_volumes-vnf

several_volumes_vnf/several_volumes_vnfd.yaml

+vnfd:
+  description: A basic VNF descriptor w/ one VDU and several volumes
+  df:
+  - id: default-df
+    instantiation-level:
+    - id: default-instantiation-level
+      vdu-level:
+      - number-of-instances: 1
+        vdu-id: several_volumes-VM
+    vdu-profile:
+    - id: several_volumes-VM
+      min-number-of-instances: 1
+  ext-cpd:
+  - id: vnf-mgmt-ext
+    int-cpd:
+      cpd: vdu-eth0-int
+      vdu-id: several_volumes-VM
+  id: several_volumes-vnf
+  mgmt-cp: vnf-mgmt-ext
+  product-name: several_volumes-vnf
+  sw-image-desc:
+  - id: ubuntu20.04
+    name: ubuntu20.04
+    image: ubuntu20.04
+  - id: ubuntu20.04-aws
+    name: ubuntu20.04-aws
+    image: ubuntu/images/hvm-ssd/ubuntu-artful-17.10-amd64-server-20180509
+    vim-type: aws
+  - id: ubuntu20.04-azure
+    name: ubuntu20.04-azure
+    image: Canonical:UbuntuServer:20.04-LTS:latest
+    vim-type: azure
+  vdu:
+  - id: several_volumes-VM
+    name: several_volumes-VM
+    sw-image-desc: ubuntu20.04
+    alternative-sw-image-desc:
+    - ubuntu20.04-aws
+    - ubuntu20.04-azure
+    virtual-compute-desc: several_volumes-VM-compute
+    virtual-storage-desc:
+    - root-volume
+    - persistent-volume
+    - ephemeral-volume
+    int-cpd:
+    - id: vdu-eth0-int
+      virtual-network-interface-requirement:
+      - name: vdu-eth0
+        virtual-interface:
+          type: PARAVIRT
+  version: '1.0'
+  virtual-compute-desc:
+  - id: several_volumes-VM-compute
+    virtual-cpu:
+      num-virtual-cpu: "1"
+    virtual-memory:
+      size: "1.0"
+  virtual-storage-desc:
+  - id: root-volume
+    #type-of-storage: root-storage
+    size-of-storage: "10"
+  - id: persistent-volume
+    type-of-storage: persistent-storage
+    size-of-storage: "1"
+  - id: ephemeral-volume
+    type-of-storage: ephemeral-storage
+    size-of-storage: "2"
+