Add connectivities sub-component to "network" namespace.

Add connectivities element, which is sequence of "connectivity".

Add connectivity element, which has properties:

• connectivity-id
• bandwidth-profile-name
• vpn-type
• EIR
• CBS
• EBS
• colorAware
• couplingFlag
• etht-svc-name
• access-provider-id
• access-client-id
• access-topology-id
• access-node-id
• access-ltp-id
• connectivity-selflink
• cvlan
• operational-status
• model-customization-id
• model-version-id
• model-invariant-id

Make the following properties indexed and searchable:

• connectivity-id
• etht-svc-name
• operational-status