Add Python version of the edge driver library

[KavanPrice]

Overview

This adds a Python version of the JavaScript edge driver library to allow easy creation of edge drivers in Python. Python is often used by end users to interact with devices, so is a useful language for people to write their own drivers in as we move more towards a BYOD model.

The source is written as close to the original JS as possible with the addition of type hints from typing.

Building

This project was written using Poetry as a build system but can be used with any build system.

Testing

Simple unit tests have been implemented for this project. They require pytest to run. You can run these tests using pytest tests/.

[KavanPrice]

I've now made this such that drivers are intended to be run inside asyncio.run(). This simplifies greatly what I was trying to do with the internal async handling but we're now imposing restrictions on the library caller.

[amrc-benmorrow]

Nearly there, I think. Has this had any real-world-ish testing against an actual Edge Agent?

[amrc-benmorrow]

You can handle these superclass arguments more cleanly like this:

def __init__(self, serial: bool = False, **opts):
    super().__init__(**opts)
    self.serial_mode = serial

This way if the arguments to Driver change the subclasses don't need changing.

[amrc-benmorrow]

You need to default the ports correctly here. The standard ACS deployment passes mqtt://localhost and expects the driver to understand port 1883. This is an irritating deficiency in urllib.