fix(pool): fix race condition in paymaster tracking

[dancoombs]

Proposed Changes

• Fix race condition

Race

1. Paymaster sends deposit transaction
2. UO uses paymaster, paymaster is new to the pool, queries chain for balance and adds to cache, sees the balance from 1
3. Deposit event from (1) is notified to the pool, balance is added to the balance from (2)

Since there is no ordering guarantee between (2) and (3) you can end up with either balance or 2x balance in the cache.
Instead process events as a reset event, and just query the chain for a balance after an event.

[codecov]

Codecov Report

Attention: Patch coverage is 98.91892% with 2 lines in your changes missing coverage. Please review.

Project coverage is 55.31%. Comparing base (98f8e2c) to head (bc64d0a).

Additional details and impacted files

Files	Coverage Δ
crates/pool/src/mempool/paymaster.rs	93.40% <100.00%> (-0.22%)	⬇️
crates/pool/src/mempool/uo_pool.rs	95.09% <99.31%> (+0.34%)	⬆️
crates/rpc/src/eth/error.rs	0.00% <0.00%> (ø)

Flag	Coverage Δ
unit-tests	55.31% <98.91%> (+0.10%)	⬆️

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	50.00% <ø> (ø)
dev	0.00% <ø> (ø)
pool	64.64% <99.45%> (+0.26%)	⬆️
provider	16.68% <ø> (ø)
rpc	25.66% <0.00%> (-0.02%)	⬇️
sim	77.86% <ø> (ø)
tasks	∅ <ø> (∅)
types	65.45% <ø> (ø)
utils	18.28% <ø> (ø)

[dphilipson]

Great catch, thanks for fixing!