[Cashtab][Alias] Deprecate getAliasServerState
Summary:
T3216
Following the removal of the /state endpoint on the alias-server, the getAliasServerState function is no longer in use.
Test Plan:
grep -r getAliasServerState src/
npm test
Reviewers: bytesofman, #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D14319