ZIP-244: Implement Non-Malleable transaction ids

[teor2345]

Is your feature request related to a problem? Please describe.

ZIP-244 defines a new transaction digest algorithm currently planned to be applied from the NU5 network upgrade onward.

ZIP-244 creates non-malleable transaction identifiers that commit to all transaction data except for attestations to transaction validity. (That is, signatures and proofs.)

Describe the solution you'd like

We should implement or integrate this new transaction digest algorithm in Zebra as per:

• https://zips.z.cash/zip-0244
• https://zips.z.cash/zip-0225#modifications-to-zip-244

This will include:

Non-malleable transaction ids

• implement non-malleable transaction ids using librustzcash
• update the transaction merkle tree to use non-malleable transaction IDs in NU5 (Zebra-specific, depends on ZIP-244: Create generic transaction id merkle tree #2049)

Alternative Implementations

The ECC have implemented a version of this in Rust in the librustzcash library, we should be able to either port some of that code or learn from that code to implement the Zebra version.