[NevynUK]

The ESP32 chip defaults to country code 01 which is the world safe contry code. This limits some operations such as WiFi power but also the ability to find a WiFi network if the network is marked as hidden.

This change adds the ability to set the country code in the meadow.config.yaml file.

Valid country codes are:

"01", "AT", "AU", "BE", "BG", "BR", "CA", "CH", "CN", "CY", "CZ", "DE", "DK", "EE", "ES", "FI", "FR", "GB", "GR", "HK", "HR", "HU", "IE", "IN", "IS", "IT", "JP", "KR", "LI", "LT", "LU", "LV", "MT", "MX", "NL", "NO", "NZ", "PL", "PT", "RO", "SE", "SI", "SK", "TW", "US"

[NevynUK]

So a valid entry in the meadow.config.yaml file for the country code looks something like this:

Network:
    Interfaces:
        - Name: WiFi
          UseDHCP: true
          IPAddress: 192.168.1.16
          NetMask: 255.255.255.0
          Gateway: 192.168.1.254
    #
    #   Which interface should be used?
    #
    DefaultInterface: WiFi
    #
    #    Country code for the WiFi network.
    #
    CountryCode: GB