trie: separate hashes and committer, collapse on commit

* trie:  make db insert use size instead of full data

* core/state: minor optimization in state onleaf allocation

* trie: implement dedicated committer and hasher

* trie: use dedicated committer/hasher

* trie: linter nitpicks

* core/state, trie: avoid unnecessary storage trie load+commit

* trie: review feedback, mainly docs + minor changes

* trie: start deprecating old hasher

* trie: fix misspell+lint

* trie: deprecate hasher.go, make proof framework use new hasher

* trie: rename pure_committer/hasher to committer/hasher

* trie, core/state: fix review concerns

* trie: more review concerns

* trie: make commit collapse into hashnode, don't touch dirtyness

* trie: goimports fixes

* trie: remove panics