[alias-server] move to apps/ folder

Summary:
T3067

Move alias-server to apps/ folder. Update .arclint and CI build instructions accordingly.

Test Plan:
From root of repo, git grep "web/alias-server" and no output
Test CI with new dir
arc lint --everything

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D13580