NEC plugin: Rename quantum_id column to neutron_id

ID mapping tables in NEC plugin had columns named quantum_id.
This commit renames them to neutron following project renaming.

Closes-Bug: #1287432
Change-Id: I0669defba7189d5b8259365d88d67db51a28c764
Merge "NEC plugin: Rename quantum_id column to neutron_id"