Implement Hash params for shareable links

[Koopzington]

Something along the lines of https://anitools.koopz.rocks#tool=BetterList&mediaType=ANIME&userName=Koopz ...
Which would then result in the frontend being initialized with these values.
At a later point we could also add support for filters to be passed this way as well.

[Koopzington]

Alternatively add a "share" function to the backend which stores all the params and use hashes in the links to keep things short, since otherwise they might turn out to be uncomfortably long