[alias-server] Add avalancheCheckWaitInterval as a parameter to prevent 10s delays in unit tests

Summary:
T3060

Depends on D13631

App should wait ~10s before checking if a found block is avalanche finalized. We don't want to do this in unit tests.

So, make this a parameter and pass to all required functions.

Test Plan:
npm test
npm test

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D13633