feat: add Task methods to make _asyncio more similar to cpython

[imnotjames]

This updates the way that Task is handled in the C module for asyncio which implements tasks & task queues. The goal is to bring asyncio in CircuitPython slightly closer to CPython.

This adds the following methods to Task:

• get_coro() - how CPython exposes the coroutine backing the task (CPython Docs)
• result() - a helper method from CPython for returning the successful response (CPython Docs)
• exception() - a helper method from CPython for returning the raised values (CPython Docs)
• cancelled() - helper for true / false if the task has been cancelled (CPython Docs)
• add_done_callback() - adds a callback to the task for completion or if already complete executes it (CPython docs)
• remove_done_callback() - removes a specific "done" callback from the task (CPython docs)

Moves CancelledError & creates InvalidStateError in the extmod

Adds a hash unary operation so Tasks can be added to sets.

To Do:

• Support add_done_callback / remove_done_callback
• Add tests for new features

[imnotjames]

Tests are going to fail until adafruit_asyncio uses the CancelledError from _asyncio. Opened adafruit/Adafruit_CircuitPython_asyncio#55 for this unless there's a different way this should be handled.

[dhalbert]

You will need to advance the submodule commit for the asyncio library.

[imnotjames]

I'm trying my luck upstream first - micropython#13000 - I'll close this PR out for the time being. Hopefully can just port this back here!

[dhalbert]

We usually don't merge from MicroPython upstream until they release a major version, so if it looks like this is approximately the way it's going to go, fine to leave this open. Once you update the asyncio submodule here, I think the tests will run?