wip: initial utf8 support take 2

[Conni2461]

This will replace https://github.com/nvim-telescope/telescope-fzf-native.nvim/pull/10

Its easier that way because rebasing would be a nightmare, a lot changed in the c code in the past month

I try to implement case for utf8 strings + normalize. Example: I have a Ö somewhere and i want to be able to match it with ö (lowercase) and o (normalize).