Flutter completions for fish

This is simply the output of qiuxiang/flutter-fish-completions. Before it was written suboptimaly by hand.

Installation

Note New version of qiuxiang/flutter-fish-completions support fisher so you can install it with
fisher install qiuxiang/flutter-fish-completions

Install with fisher :

fisher install jduchateau/fish-flutter-completions

Otherwise, you could copy the file in your fish directory (typically in ~/.config/fish/completions).

You should thank qiuxiang for the tool, and me for running it :)