Make `TreeDiff` utilities available in `cardano-ledger-binary`

Currently the test logs from the tests in `cardano-ledger-binary` are really hard to read. I think many of them could be improved with `tree-diff`, but our testing utilities for `tree-diff` are defined in `cardano-ledger-core`, which can't be a dependency of `cardano-ledger-binary`. Perhaps it would make sense to create a new package called `cardano-ledger-test-utils` that all the other testlibs can depend on.