[alias-server] rename unit test files

Summary:
T3060

In building the last stack, I found it super confusing that the unit test files were named the same as their reference files...even if in a different directory.

Patching that here.

Test Plan:
Confirm change is just file names
npm test still passes

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D13513