Add support for fuzzy searching labels using public API
Summary
As a part of ~performance improvement by not loading all the labels at once in Labels Select dropdown, we want to move searching to API level. Currently, frontend uses fuzzaldrin-plus
to perform local fuzzy searching of all the labels within the dropdown. But as search and scroll performance of labels dropdown is slow in general due to increased number of labels, it makes sense not to do any searching on frontend.
With !44415 (merged), we added plain search
param support to Labels API, but since fuzzy searching is frequently used by GitLab users (as brought up in #250727 (closed)), it makes sense to add optional fuzzy
param support to labels API so that !43874 (merged) can start using it.