fix: make getUtxos address/maxUtxos filter work

[pedroferreira1]

Motivation

The filter by address and max utxos is not working in the utxos/outputs API. It seems like a recent upgrade changed the way lambda gets multi value query string.

Acceptance Criteria

• Fix filter by address and max utxos.

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged
• Make sure either the unit tests and/or the QA tests are capable of testing the new features
• Make sure you do not include new dependencies in the project unless strictly necessary and do not include dev-dependencies as production ones. More dependencies increase the possibility of one of them being hijacked and affecting us.

[pedroferreira1]

This test show that it used to work.