Update tests for AssetBase derivation and key components

[vivek-arte]

This PR updates the test-vectors from the updates to the zcash-test-vectors repository (see here).

The keys test is also updated to now use the asset base from the test vectors instead of just using the native asset.

[what-the-diff]

PR Summary

• Asset base derivation: The asset base is now derived from the issuance validating key and description for improved accuracy.
• Error handling update: AssetBase::from_bytes() has been updated to return an error for incorrect input lengths instead of causing a panic.
• NoteValue::asset_base() change: This function now returns a reference to itself for all note values, including native ones using AssetBase::default(). This resolves previous test failures in relation to asset bases.
• Test vector updates: Adjustments have been made to the test vectors in src\note\asset_id\testing to align with the new changes.

[PaulLaux]

Very nice, same comment for a concise PR description and git commit msg as in QED-it/zcash-test-vectors#7 (review)

Make sure to describe the change to the keys test.