feat: replay flashblocks to validator for latency benchmarking

[mw2000]

Description

Add flashblock replay server that emits collected flashblock payloads to validator clients via websocket during benchmark runs.

Fixes #152

Testing

Ran this and saw this emitted logs that flashblocks have been replayed

./bin/base-bench run \
  --config ./configs/examples/rbuilder.yml \
  --root-dir ./test-flashblocks \
  --output-dir ./output-flashblocks \
  --rbuilder-bin ./bin/op-rbuilder \
  --reth-bin ./bin/op-reth \
  --geth-bin ./bin/geth 

[cb-heimdall]

✅ Heimdall Review Status

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Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2

[meyer9]

Looks great! Left a few small comments on some improvements, but overall looks very clean!

[meyer9]

LGTM!