feat(api/mymdc): fetch MyMDC queries asynchronously

[CammilleCC]

To avoid blocking the API server during MyMDC fetches, we’re now using aiohttp to handle queries asynchronously. The main slowdown is still from globbing the filesystem for DAMNIT directories, but hopefully, we can work around that in the future.

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One can test it by adding the following at the of the metadata/proposals.py:

async def main():
    # print(await get_proposal_info(proposal_num="2956", use_cache=False))
    # print(await get_damnit_proposals(use_cache=False))
    print(await get_available_proposals(user_groups=["scsdata"], use_cache=False))


if __name__ == "__main__":
    import asyncio
    asyncio.run(main())

And run python -m damnit_api.metadata.proposals.