test: add assert_invariants

[mattsse]

add assert_invariants function for txpool

enforced on drop for test

[codecov]

Codecov Report

Merging #4623 (632bd8c) into main (62e7d98) will decrease coverage by 0.03%.
The diff coverage is 96.42%.

Files Changed	Coverage Δ
crates/transaction-pool/src/pool/pending.rs	83.12% <83.33%> (+<0.01%)	⬆️
crates/transaction-pool/src/pool/blob.rs	15.49% <100.00%> (+3.72%)	⬆️
crates/transaction-pool/src/pool/parked.rs	80.31% <100.00%> (+0.31%)	⬆️
crates/transaction-pool/src/pool/txpool.rs	73.00% <100.00%> (+0.34%)	⬆️

... and 12 files with indirect coverage changes

Flag	Coverage Δ
integration-tests	16.76% <0.00%> (-0.02%)	⬇️
unit-tests	64.02% <96.42%> (-0.03%)	⬇️

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

Components	Coverage Δ
reth binary	31.08% <ø> (ø)
blockchain tree	83.58% <ø> (ø)
pipeline	90.53% <ø> (ø)
storage (db)	75.32% <ø> (ø)
trie	94.84% <ø> (-0.04%)	⬇️
txpool	49.87% <96.42%> (+0.23%)	⬆️
networking	77.22% <ø> (-0.14%)	⬇️
rpc	57.40% <ø> (ø)
consensus	63.40% <ø> (ø)
revm	31.56% <ø> (ø)
payload builder	8.97% <ø> (ø)
primitives	86.52% <ø> (-0.03%)	⬇️