Handle duplicate SwitchingSubnet identifiers

[jmacauley]

When the SENSE-O "reapplies" a delta template it will reuse all the MRML identifiers defined in the template. If the SENSE-N-RM has seen a request from this delta template before then it will already have NSI connections with the SwitchingSubnet identifier stored in the NSI reservation description. When a delta reduction for this second delta is received it will have a SwitchingSubnet identifier matching multiple reservations. The current programatic flow will query the reservation looking for matching descriptions, resulting in two matching reservations. Code has been added to not try a terminate on an already terminated reservation, however, a connectionId mapping into the MRML operationMap may be a better solution to keep a list of reservation ids to terminate.

There is an additional issue of timing between issuing the reservation operation, getting a connectionId in response, and the arrival of the reserveConfirmed. May need to look at correlationId for updating reservation entries.