As a technician I would like to be able to assign/unassign assets to/from users

As a technician I will need the ability to assign new assets to users and remove assets they have assigned to them. This should be audited so we can see the history of an asset, how it has changed over it's lifetime and where it has been.
## Audit Information
- Date asset was assigned
- Reason it was assigned (replacement, new starter, etc...)
- who it was assigned to
