Feature: Add min/max fields for device field definitions

[RaulTrombin]

Protocols as JSON Schema allow us to validate messages — not only their structure but also their content and limits.

example of a auto-generated jsonschema part:

....
        "gain_setting": {
          "description": "Analog gain setting (0 = low, 1 = normal, 2 = high)",
          "type": "integer",
          "format": "uint8",
          "maximum": 255,
          "minimum": 0
        },
....

The maximum and minimum could be set directly to 2 and 0,
but the current definitions/ping360 doesn't contain the min/max fields,
which would allow us to automate protocol definitions like this.

Current definitions:

....
                    {
                        "name": "gain_setting",
                        "type": "u8",
                        "description": "Analog gain setting (0 = low, 1 = normal, 2 = high)"
                    },
....