Pico 2 W OTA Update Example

[will-v-pi]

Adds an example of Pico 2 W OTA update

Requires raspberrypi/pico-sdk#1969

[andygpz11]

I think the README.md will need to be updated to include this example.

[peterharperuk]

1/ How do I know this is really working? I really think this needs a readme with the example to tell someone how to run the example to perform an update etc. I see it downloading the update and rebooting but it doesn't change anything.
2/ I'm not sure why the python script is in the python_test_tcp folder (not really sure I remember why we have that folder). If we're going to stick all python scripts in there we should probably rename the folder. Or just stick the script with the ota_update
source?
3/ Do we need poll and background versions of the firmware uf2s? Maybe it would be less confusing to just build one version of this example (just use background threadsafe?)

[will-v-pi]

Thanks - I've added a readme with details of how to use it, moved the python script, and removed the poll version

[peterharperuk]

Thanks - works nicely following the instructions