Overhaul lookup to be more effective

Replaced the internal lookup system, which was hugely prone to issues with concurrent users and failed easily on extra lines being returned (see [reddit](https://www.reddit.com/r/admincraft/comments/2gkp39/fishbans_updates_live_mcbans_data_is_back_and_more/ckm0138))
We are using my API (which original is located at [my org's repo](https://github.com/AE97/FishbansAPI)) which is able to handle all those issues, including caching and invalid names.