refactor(driver/proposer): refactor some code in review

[alexshliu]

No description provided.

[github-actions]

Hive test result:
failed: 1, detail: http://hive.a1.taiko.xyz/?page=v-pills-results-tab&suite=1676564060-80598f099ca92f641483b7269a391674.json

[codecov]

Codecov Report

Merging #152 (97e7587) into main (f281121) will decrease coverage by 2.02%.
The diff coverage is 78.78%.

@@            Coverage Diff             @@
##             main     #152      +/-   ##
==========================================
- Coverage   58.32%   56.30%   -2.02%     
==========================================
  Files          34       35       +1     
  Lines        3323     3417      +94     
==========================================
- Hits         1938     1924      -14     
- Misses       1140     1253     +113     
+ Partials      245      240       -5     

Impacted Files	Coverage Δ
bindings/encoding/input.go	40.18% <ø> (-0.56%)	⬇️
driver/chain_syncer/beaconsync/syncer.go	0.00% <0.00%> (ø)
driver/chain_syncer/calldata/syncer.go	49.37% <ø> (ø)
driver/driver.go	64.40% <50.00%> (+4.40%)	⬆️
driver/chain_syncer/chain_syncer.go	37.00% <71.42%> (+0.15%)	⬆️
driver/chain_syncer/beaconsync/progress_tracker.go	77.92% <82.85%> (ø)
driver/config.go	70.00% <100.00%> (ø)
proposer/pool_content_splitter.go	65.93% <100.00%> (ø)
proposer/proposer.go	59.29% <100.00%> (-0.36%)	⬇️
prover/prover.go	55.00% <0.00%> (-5.00%)	⬇️
... and 3 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[davidtaikocha]

Changes are included in #153