feat: Remove the store/internal module (#18944)

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

store/internal/tree/hash.go

@@ -1,68 +0,0 @@
-package tree
-
-import (
-	"crypto/sha256"
-	"hash"
-	"math/bits"
-)
-
-var (
-	leafPrefix  = []byte{0}
-	innerPrefix = []byte{1}
-)
-
-// HashFromByteSlices computes a Merkle tree where the leaves are the byte slice,
-// in the provided order. It follows RFC-6962.
-func HashFromByteSlices(items [][]byte) []byte {
-	return hashFromByteSlices(sha256.New(), items)
-}
-
-func hashFromByteSlices(sha hash.Hash, items [][]byte) []byte {
-	switch len(items) {
-	case 0:
-		return emptyHash()
-	case 1:
-		return leafHashOpt(sha, items[0])
-	default:
-		k := getSplitPoint(int64(len(items)))
-		left := hashFromByteSlices(sha, items[:k])
-		right := hashFromByteSlices(sha, items[k:])
-		return innerHashOpt(sha, left, right)
-	}
-}
-
-// returns tmhash(0x00 || leaf)
-func leafHashOpt(s hash.Hash, leaf []byte) []byte {
-	s.Reset()
-	s.Write(leafPrefix)
-	s.Write(leaf)
-	return s.Sum(nil)
-}
-
-func innerHashOpt(s hash.Hash, left, right []byte) []byte {
-	s.Reset()
-	s.Write(innerPrefix)
-	s.Write(left)
-	s.Write(right)
-	return s.Sum(nil)
-}
-
-// returns tmhash(<empty>)
-func emptyHash() []byte {
-	h := sha256.Sum256([]byte{})
-	return h[:]
-}
-
-// getSplitPoint returns the largest power of 2 less than length
-func getSplitPoint(length int64) int64 {
-	if length < 1 {
-		panic("Trying to split a tree with size < 1")
-	}
-	uLength := uint(length)
-	bitlen := bits.Len(uLength)
-	k := int64(1 << uint(bitlen-1))
-	if k == length {
-		k >>= 1
-	}
-	return k
-}