Enhance ReST API for hardware inventory:

* Retrieve the root entity (all hardware inventory)
GET /nodes/{nodeId}/hardwareInventory

* Override the root entity (all hardware inventory)
POST /nodes/{nodeId}/hardwareInventory

* Retrieve a specific entity
GET /nodes/{nodeId}/hardwareInventory/{entPhysicalIndex}

* Delete a specific entity
DELETE /nodes/{nodeId}/hardwareInventory/{entPhysicalIndex}

* Modify an existing entity
PUT /nodes/{nodeId}/hardwareInventory/{entPhysicalIndex}

* Add a child entity
POST /nodes/{nodeId}/hardwareInventory/{entPhysicalIndex}