[alias-server] Modify getValidAliasRegistrations to work with partial tx history
Summary:
T3060
The getValidAliasRegistrations function currently only works if input is full history of all txs with valid alias prefix and fee.
Allow this function to take a parameter of previously valid registered aliases to return only newly registered aliases.
Test Plan: npm test
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D13720