Make tilecloud chain async

[sbrunner]

GSGMF-2112

Currently, we use process and thread who has relay erratic and difficult to understand comportment, And with the Python global lock, I think that's not performant.

This pull reqest will:

• Remove all the thread and process
• Use async to have concurrent task
• Limit the parallel request on a host

Note that some code have been copied from TileCloud to make it async

Used:

• https://docs.sqlalchemy.org/en/20/orm/extensions/asyncio.html
• https://docs.aiohttp.org/en/stable/index.html
• https://learn.microsoft.com/en-us/samples/azure/azure-sdk-for-python/storage-blob-samples/

Todo to make the HTTP server async:

• Migrate to FastAPI on uvicorn

Will be used

• ASGI: https://asgi.readthedocs.io/en/latest/implementations.html
• https://github.com/fastapi/fastapi
• https://www.uvicorn.org/
• https://redis.readthedocs.io/en/stable/examples/asyncio_examples.html
• https://github.com/trallnag/prometheus-fastapi-instrumentator
• Some function of c2cwsgiutils should be migrated to async

Open question:

• What we need from c2cwsgiutils that's not present in prometheus-fastapi-instrumentator?