Support for custom hostname in settings.toml

[makermelissa]

This is from circuitpython/web-editor#266

Would like a way to do the equivalent of setting wifi.radio.hostname="newhostname" prior to calling wifi.radio.connect(), but via settings.toml so that the CPy dhcp client requests "newhostname" along with requesting an IP address. This way it would take effect when using web workflow.

I tried assigning to CIRCUITPY_WEB_INSTANCE_NAME but that didn't seem to affect what hostname the dhcp client requests. Presumably something like CIRCUITPY_WIFI_HOSTNAME would be more appropriate.

I'm not sure if the issue had previously been opened, but if so, feel free to close this.