uasyncio.queues: Add simple implementation of asynchronous queues for uasyncio

Hi, I've added simple port of asyncio.queues.Queue. It can be a bit slow, but works well for me.
For testing:
```bash
cd uasyncio.queues/tests
micropython test.py
```
"depends" in metadata.txt are runtime dependencies, maps to "install_requires" in setup.py. I'm sure unittest is not required for normal running, only for testing. There's currently no support to specify test dependencies in metadata.txt, if you think it's important, please add that, otherwise, just dropping it from here should be good enough for now.