Feat: fuzzy matching flag -z

[wintermute-cell]

Adds the option to use fuzzy matching when filtering menu items, along with the necessary flag and usage info.

Port of / strongly inspired by: https://tools.suckless.org/dmenu/patches/fuzzymatch/dmenu-fuzzymatch-4.6.diff

Would close https://github.com/Cloudef/bemenu/issues/367

[m0tholith]

Bumping this, totally works and no issues

[bitkeen]

@Cloudef could you review this please?

[Cloudef]

Sorry for taking so long. It looks good to me.

[wintermute-cell]

thank you!

[Cloudef]

Hello, I reverted these changes because static analysis found bugs in the code. The CI probably did not find those because it was running older version of the compiler at the time of PR. Also, I think this feature should be implemented as separate function rather than in the default filter_dmenu_fun as dmenu has mechanism for selectable filters here https://github.com/Cloudef/bemenu/blob/master/lib/menu.c#L44-L47. If you send a revised PR, I'll review it again.