Analyze if we can easily develop an AsyncEthereumClient

[Uxio0]

Context

• Web3 supports async providers. It should be posible for us to do the same and allow people using async frameworks like FastAPI to use our EthereumClient
• AsyncWeb3 must be used instead of Web3
• Calls to self.http_session.post should be refactored to something similar to self.post_request or similar, so we don't expose what library are we using
• Instead of requests, we aioHTTP must be used

Analyze if we can implement something similar with not much overhead. That might not be posible with our current implementation. If after the analysis we decide it takes more than one sprint to implement, we should meet and decide what to do