feat(error): use unexpected error instead

[0xfourzerofour]

Proposed Changes

• Log pool closed error and just propagate the UnexpectedResponse error instead. We do not really want to be saying that the pool sender has closed in rpc responses
• Check that the gas price is not equal to zero before calculating the dynamic gas as this will lead to an integer overflow

[codecov]

Codecov Report

Attention: Patch coverage is 36.36364% with 7 lines in your changes missing coverage. Please review.

Project coverage is 57.55%. Comparing base (a88a4c7) to head (1543057).

Files	Patch %	Lines
crates/pool/src/server/local.rs	50.00%	4 Missing ⚠️
crates/sim/src/gas/gas.rs	0.00%	3 Missing ⚠️

Additional details and impacted files

Files	Coverage Δ
crates/sim/src/precheck.rs	77.55% <ø> (+0.15%)	⬆️
crates/sim/src/gas/gas.rs	82.38% <0.00%> (-1.75%)	⬇️
crates/pool/src/server/local.rs	47.63% <50.00%> (-0.25%)	⬇️

Flag	Coverage Δ
unit-tests	57.55% <36.36%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
rundler binary	0.00% <ø> (ø)
builder	60.59% <ø> (ø)
dev	0.00% <ø> (ø)
pool	64.46% <50.00%> (-0.03%)	⬇️
provider	16.10% <ø> (ø)
rpc	25.63% <ø> (ø)
sim	78.49% <0.00%> (-0.05%)	⬇️
tasks	∅ <ø> (∅)
types	66.68% <ø> (ø)
utils	18.28% <ø> (ø)