Device setup is not working with 1.3.8

[umbynos]

Describe the problem

In #878 we removed network upload functionality. Unfortunately, the device setup flow used an hack to invoke the arduino-fwuploader tool:

{
  "board": "arduino:renesas_uno:unor4wifi",
  "port": "/dev/cu.usbmodemDC5475C5557C2",
  "commandline": "\"{runtime.tools.arduino-fwuploader.path}/arduino-fwuploader\" firmware flash {network.password} -v --retries 5",
  "signature": "...",
  "filename": "UpdateFirmware.bin",
  "extra": {
    "auth": {
      "password": "-a /dev/cu.usbmodemDC5475C5557C2 -b \"arduino:renesas_uno:unor4wifi\""
    }
  },
  "hex": ""
}

As you can see extra.auth.password is used to pass additional info to the command-line. The auth struct was removed here because it was part of the network upload
This hack was used because the agent was not providing a functionality to specify the fqbn in the commandline

To reproduce

Just manually downgrade the Wi-Fi firmware of a board (like the UNO R4 WiFi) and then perform the device setup.

Expected behavior

The board is provisioned correctly

Arduino Create Agent version

1.3.7/1.3.8

Operating system

N/A

Operating system version

N/A

Browser

N/A

Browser version

N/A

Additional context

N/A

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest version
• My report contains all necessary details

[umbynos]

Fixed in #905