fix: manually implements arbitrary for TxValue

[joshieDo]

Any test (such as iai bench) that relies on generating arbitrary/proptest TxValue and eventually calls to_compact can currently fail if it generates a U256 bigger than u128.

Until we break the database again and unify the types, we need to manually implement the arbitrary as well.

[codecov]

Codecov Report

Merging #4907 (109ca9e) into main (1c39b37) will decrease coverage by 0.01%.
Report is 1 commits behind head on main.
The diff coverage is 100.00%.

Files	Coverage Δ
crates/primitives/src/transaction/tx_value.rs	98.64% <100.00%> (+0.40%)	⬆️

... and 10 files with indirect coverage changes

Flag	Coverage Δ
integration-tests	15.50% <0.00%> (-0.01%)	⬇️
unit-tests	62.65% <100.00%> (-0.01%)	⬇️

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

Components	Coverage Δ
reth binary	32.58% <ø> (ø)
blockchain tree	80.64% <ø> (ø)
pipeline	88.45% <ø> (ø)
storage (db)	73.32% <ø> (ø)
trie	94.52% <ø> (+0.03%)	⬆️
txpool	49.10% <ø> (-0.02%)	⬇️
networking	76.09% <ø> (-0.02%)	⬇️
rpc	57.71% <ø> (-0.04%)	⬇️
consensus	61.05% <ø> (ø)
revm	28.47% <ø> (ø)
payload builder	8.16% <ø> (ø)
primitives	85.46% <100.00%> (+0.02%)	⬆️

[gakonst]

👍