FR: Add location to old asset when swapping an assigned assets on a device

[sol1-matt]

• go to a object (eg: device) with an asset already assigned
• edit the assignment

The url will be https://netbox.example.com/plugins/inventory/assets/device/1234/reassign/

for the old asset (the one being removed) the only option is to change the old assets status
the option to choose where the asset goes, site and location, would be useful here