proxy: refactor

[chirag-parmar]

Verified proxy consists fo two components the verifying algorithms and the proxy. This PR logically splits the verification engine from the proxy. The proxy is further broken down into seperate client and server implementations that connect to the verification engine as backend and frontend resp.

[tersec]

I'm not sure why it's not triggering in the CI, but when I make nimbus_verified_proxy locally in this branch, I get:

nimbus-eth1/nimbus_verified_proxy/engine/engine.nim(10, 58) Error: duplicate import of 'header_store'; previous import here: nimbus-eth1/nimbus_verified_proxy/engine/engine.nim(10, 17) [DuplicateModuleImport]

which appears to indeed be the case:

nimbus-eth1/nimbus_verified_proxy/engine/engine.nim

Line 10 in 775421c

import ./types, ./header_store, ./utils, ./rpc_frontend, ./header_store, ./evm

[tersec]

nimbus-eth1/nimbus_verified_proxy/nimbus_verified_proxy.nim(48, 30) Hint: 'e' is declared but not used [XDeclaredButNotUsed]

Can just omit the as e, e.g.

    except CatchableError:

Separately, there are a lot of CatchableError references throughout, but that can be addressed via a separate comment. As far as this specific one goes, it's just the XDeclaredButNotUsed.

[chirag-parmar]

good catch

[arnetheduck]

that said, almost every time you do catch CatchableError in async code, you must also propagate CancelledError, ie catch and reraise it: https://www.youtube.com/watch?v=1bBVQaAD_jI

[chirag-parmar]

Did you intend to attach some other link to this comment? or is there a metaphorical meaning to the video?

[kdeme]

🚔

[chirag-parmar]

606c8db @arnetheduck returning cancelled error now. changed it wherever CatchableError was caught but no other error was propagated.