core/types: use stacktrie for derivesha

trie: add stacktrie file

trie: fix linter

core/types: use stacktrie for derivesha

rebased: adapt stacktrie to the newer version of DeriveSha
Co-authored-by: Martin Holst Swende <martin@swende.se>

More linter fixes

review feedback: no key offset for nodes converted to hashes

trie: use EncodeRLP for full nodes

core/types: insert txs in order in derivesha

trie: tests for derivesha with stacktrie

trie: make stacktrie use pooled hashers

trie: make stacktrie reuse tmp slice space

trie: minor polishes on stacktrie

trie/stacktrie: less rlp dancing

core/types: explain the contorsions in DeriveSha

ci: fix goimport errors

trie: clear mem on subtrie hashing

squashme: linter fix

stracktrie: use pooling, less allocs (#3)

trie: in-place hex prefix, reduce allocs and add rawNode.EncodeRLP

Reintroduce the `[]node` method, add the missing `EncodeRLP` implementation for `rawNode` and calculate the hex prefix in place.
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Martin Holst Swende <martin@swende.se>