A lot of places were relying on AK/Traits.h to give it strnlen, memcmp,
memcpy and other related declarations.
In the quest to remove inclusion of LibC headers from Kernel files, deal
with all the fallout of this included-everywhere header including less
things.
A StringView is sufficient here. This also removes the declaration of
fuzzy_match_recursive from the header, as it's only needed from within
the implementation file.