feat: Allow abbreviations for long option names

eza is one of those commands that can be invoked often. As such, it is important to optimize it for minimal number of key strokes, IMO.

One way to do it is to allow for abbreviation long option names, as long as they are unambiguous. For example `eza --abs` should be equivalent to `eza --absolute`, as long as there are no other long options that start with "abs". Same with `eza --ab`, `eza --abso` etc...

Currently, "unknown argument" error is thrown.

This is especially important for those options that only have long names. I imagine there will be more such options in the future, so it will be getting more important with time.