Local websocket endpoint for flashblocks stream

[krif24]

When dealing with low-delay applications one needs to have a stream of flashblocks in every app. It would be more effective to receive it from local op-reth rather to maintain multiple connections to external wss:// endpoints which often have a strict connection limit. What do you think about implementing retranslation of flashblocks to local consumers in reth?

[mattsse]

@loocapro might have some ideas here as well,

not opposed to simply forwarding these via an additional subscription endpoint and maybe even for the executed flashblocks as well