FediLookup

Improve command suggestions, and use server-side translations for text output rather than Placeholders (possible security fix too).

Now, the command suggestions for the /fedi who and /fedi reverse commands actually narrow what they return when more is typed, following the expected behaviour.

I've removed the bundled dependency on Text Placeholders API and added Server Translations API because I'm now using translation strings instead of text literals throughout. Theoretically, one could use a server datapack to add more languages. Pull requests adding translations are welcome, though I can't guarantee I'll accept because I only speak English so would need to find someone else to independently check for quality. This also fixes a small possible security issue I thought of (to my knowledge no-one else has found it) where someone could put a placeholder tag in their username and it would display with the placeholder evaluated in some cases.