CSV Export for Devices fails for Devices without complete information

[iacco]

Describe the bug
Following a mistake while updating tags on a device, some disconnected devices went in Unknown state.

The "Export to CSV" feature for Devices fails to download the Unknown devices information (which for the most part will be N/A), therefore creating a misalignment between the Console and the CSV.

The mistake which lead to this is a PUT request on /{scopeId}/devices/{deviceId} in order to update the tags: I thought the REST API call worked as a PATCH, and populated only the tagIds field, hence "defaulting" the other properties.
Even though this REST call could be made more user-friendly, actually the behavior is compliant with REST Verbs, so I guess it is not a problem.

To Reproduce
Steps to reproduce the behavior:

1. Connect a Device and have it listed on the Devices tab of the Console;
2. Perform a REST PUT on /{scopeId}/devices/{deviceId} updating only the tagIds to clear the device information, in order to get it into "Unknown" state;
3. Press on "Export to CSV" on the Devices tab;
4. See error.

Expected behavior
The device is present in the CSV, and its information (basically the ClientID and the Display Name if server defined) is available. Unavaliable information is printed as N/A, same as in the Console.

Screenshots
N/A

Version of Kapua
1.5.3

Type of deployment
[ ] Local Vagrant deployment
[x ] Docker
[ ] Openshift (in its variants)
[ ] Others

Main component affected
[x] Console (Chrome 96.0.4664.45)
[ ] REST API
[ ] Message Broker
[ ] - Others

Additional context
N/A