Add a fuzzy search dialog

[treagod]

This implements a fuzzy search to solve #134.

I adapted the fuzzy search from this blog and integrated it into a modal, which can be opened with Ctrl+p,

For now I want to implement the search as a plugin so that the user can opt-in as long the fuzzy search is not mature enough - but I think in the long run this functionality should be part of the core of the editor.

[jeremypw]

Sorry for not reviewing this sooner - this is some good work. Ignoring code style issues for now, here are some issues I've noticed:

1. The search dialog shows on pressing the shortcut even if there are no projects loaded.
2. The search results are not disambiguated where there are more than one project loaded
3. Clicking on a search result does not load the file (need to press Enter)
4. The search is a bit too fuzzy for my liking - some apparently poor matches appear before good or exact matches. It might be better to start with a simpler search i.e. only showing files with basenames starting with the typed letters. Later PR maybe could show different levels of match in different categories in a similar way to Files search.
5. I wonder whether it would be possible to incorporate filename search into the existing global text search function, or piggyback on it somehow. Both iterate through project files. It would then be unnecessary to create a new plugin.

[tvallois]

Hello @treagod ,

Are you still working on this? I'd be glad to help if you need to.