BL client to use httpx instead of requests

[YaphetKG]

Currently BL-lookup client in edge-normalization uses requests library. When there is a load on edge normalization server, since requests library is a blocking call, it would hang the server. Having an async client might help to avoid timeouts due to this in high load.

[cbizon]

Note, when this is done, we can drop the number of replicas in the deployment