More efficient interactionNonce -> ethTxHash

[joss-aztec]

Description

Fetch the eth tx hash for a given interaction nonce via falafel instead of scanning for it via infura.

Checklist:

• I have reviewed my diff in github, line by line.
• Every change is related to the PR description.
• There are no unexpected formatting changes, or superfluous debug logs.
• The branch has been rebased against the head of its merge target.
• I'm happy for the PR to be merged at the reviewers next convenience.
• NatSpec documentation of all the non-test functions is present and is complete.
• Continuous integration (CI) passes.
• Command forge coverage --match-contract MyContract returns 100% line coverage.
• All the possible reverts are tested.