[token-server] Link token blacklist with icon approval actions

Summary:
Add unit-tested functions for adding or removing an entry from the blacklist.

Update the telegram bot callback function to add tokenId to blacklist when icon is removed, and remove from blacklist when icon is restored. Add log statements to confirm.

Test Plan:
npm test

The telegram bot is impractical to test. The change is imo simple enough to "see if it works", given we are only adding tested functions. There's a chance the telegram API does not like that I made the callback async or some other issue. Will revert in this case.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D17041