Add TFT blacklist feature

[leMicin]

TFT has a public list of users that are blacklisted. The lists are available in public repos:

• https://github.com/The-Forbidden-Trove/ForbiddenTroveBlacklist
• https://github.com/The-Forbidden-Trove/character_name_blacklist

TFT has a rocky reputation. To ensure users don't experience any negative feelings, this will be opt-in, which means it won't be enabled by default.