change(consensus): Updates transaction verifier to use orchard::bundle::BatchValidator

[arya2]

Motivation

We want Zebra to validate orchard proofs in batches as it does for other pools.

This PR also makes some progress towards deduplicating logic in zebra-chain that's available in the orchard crate.

Closes #4672

Solution

• Adds an ItemSize trait in tower-batch-control defining an item_size() method,
• Replaces batch proof verifier Item type aliases with newtypes and implements ItemSize for them where all of them return 1 (no change in behaviour) except for the halo2 verifier which returns the number of actions in the request,
• Increments pending_items in the batch control worker by item_size() instead of 1,
• Updates HALO2_MAX_BATCH_SIZE from 2 to 64

Tests

This PR still needs tests. It also removes some tests that are no longer relevant.

Follow-up Work

Use shardtree to append to note commitment trees in parallel

PR Checklist

• The PR name is suitable for the release notes.
• The solution is tested.
• The documentation is up to date.
• The PR has a priority label.
• If the PR shouldn't be in the release notes, it has the
  C-exclude-from-changelog label.

[arya2]

This PR should use the orchard bundle created when preparing to compute transaction sighashes instead of converting orchard data to the orchard crate Bundle type twice.