feat(storage): do not require Default for derive(Compact)

[shekhirin]

Default was only needed to initalize a variable that will be instantly replaced, but it meant that we need to implement Default for all field types. It's inconvenient with enums as they often don't have any meaningful default value.

[mattsse]

I think this would be fine, can still add this manually, outside the compact macro

[joshieDo]

lgtm

[codecov]

Codecov Report

Merging #3419 (f7916a5) into main (085a703) will increase coverage by 0.01%.
The diff coverage is 100.00%.

Impacted Files	Coverage Δ
crates/storage/codecs/derive/src/compact/enums.rs	75.58% <100.00%> (ø)
crates/storage/codecs/derive/src/compact/mod.rs	94.75% <100.00%> (-0.03%)	⬇️
...rates/storage/codecs/derive/src/compact/structs.rs	81.57% <100.00%> (ø)

... and 7 files with indirect coverage changes

Flag	Coverage Δ
integration-tests	16.29% <28.00%> (-0.01%)	⬇️
unit-tests	64.30% <100.00%> (+0.03%)	⬆️

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

Components	Coverage Δ
reth binary	23.46% <ø> (ø)
blockchain tree	81.36% <ø> (ø)
pipeline	88.02% <ø> (ø)
storage (db)	73.99% <100.00%> (-0.01%)	⬇️
trie	95.64% <ø> (ø)
txpool	51.88% <ø> (+0.64%)	⬆️
networking	77.87% <ø> (-0.04%)	⬇️
rpc	58.09% <ø> (ø)
consensus/evm	46.83% <ø> (ø)
payload builder	6.83% <ø> (ø)
primitives	88.61% <ø> (-0.02%)	⬇️