feat: reorganizes use of clients and adds fallback clients

[ckartik]

• The existing clients used to communicate with arbitrary EVM-base machines have been spread throughout the code.
• Historically this would be ok, since we don't replicate the usage of these across too many services. However, given the critical nature and their susceptibility to exceptional returns, this PR purposes to move them to a single package, that can be throughly tested in place, and added to for stability improvements such as the fallback mechanism included in this PR.