Allow to enter connection details manually

[joneuhauser]

This PR essentially does two things:

• show the MAC address of the WIFI interface in the config page, in case the user needs to provide the mac address in their router (MacAuth or the likes),
• allow to set IPv4, Netmask, Gateway and DNS manually. If not provided, the existing procedure (i.e. DHCP) is used.

Also the install script causes EISDIR errors for me (probable upstream issue: micropython/micropython#9746)

I'd really like if the enviro was able to communicate via IPv6 only (then I wouldn't be having those issues), but it seems like that's not even supported by Micropython (micropython/micropython#3683) which is a shame in 2023.

Edit: Tested on Enviro Indoor Pico W. It's odd though, usually the wifi connection works for a few minutes (syncing the clock and uploading data) and then goes into wlan.state() == 1. Connecting the USB cable makes it instantly work again...

[Gadgetoid]

I've just released a firmware- and updated the CI- to bring us more up to date with upstream changes in MicroPython.

If you've got the time and inclination, a rebase would be appreciated here.