Change uniqueness_constraint for Netbox example schema post 0.14.0

[BeArchiTek]

In 0.14 with SDK 0.11, the uniqueness_constraints can only be used on non-optional attributes and relationships.

For now, I remove them from the schema to enforce them only in the mapping. Also :

• change the identifier order to make me more "readable" during the sync
• Add IPAM Builtin IP and Prefix into Netbox schema

Replace #3563