Refactor Archethic to leverage Archethic.Mining

[samuelmanzanera]

I'm wondering if we should not move this function into the Mining context, so nested modules under lib/archethic will not call the top level Archethic but the siblings' context APIs.

Hence Archethic top level module will serve only ArchethicWeb which was the motivation around Phoenix contexts.

As ArchethicWeb doesn't need at all the ContractContext

Originally posted by @samuelmanzanera in https://github.com/archethic-foundation/archethic-node/pull/1047#discussion_r1211914197