Provide shell completions for subcommands: wrap, unwrap, report

- consider at least bash, fish and zsh
- As a nice touch, generate completion files automatically from the program itself. 

Ideally a user wants to write something like `funkoverage completion zsh` and redirect the output to a folder mentioned in his `$fpath` . This feature can be used by the packager as well.

see https://github.com/junegunn/fzf?tab=readme-ov-file#setting-up-shell-integration
