[Cashtab][Alias] Deprecate getLatestAliases

Summary:
T3216

Alias caching is now being incrementally deprecated in cashtab and alias data will be retrieved directly via api endpoints. Therefore removing the getLatestAliases function.

This function's alias related interdependencies have all been deprecated prior to this diff via D14186 and D14184.

Test Plan:
npm test
grep -r getLatestAliases src/ and ensure no outputs
npm start
send a transaction, switch wallets, ensure no unexpected issues whilst alias flag in Ticker.js continues to be false

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D14199