Investigate FZF performance with the goal of removing the pre-filter

[hojberg]

We introduced a pre filter to our FZF implementation to minimize the search space, but this means we get less FZF features. For example with the pre-filter we can't search for blf to match base.List.filter.

We want to investigate our FZF implementation to learn about ways to speed it up with the goal to remove the pre-filter and take full advantage of the FZF feature set. We believe this feature set to be expected by users for Unison Local.

The pre-filter was introduced here: https://github.com/unisonweb/unison/pull/2292

[aryairani]

I started investigation at https://github.com/aryairani/fuzzy-find-test but invite anyone else to pick it up.