read_from_path should not panic without extension

[woelper]

currently, extensions are handled like this:

path.as_ref()
    .extension()
    .unwrap()
    .to_string_lossy()
    .to_string()
    .to_lowercase()
    .as_str(),

Which could panic due to the unwrap().
as try_from_ext already handles extensions, maybe we could unwrap_or into an empty OsStr or use ??

[pinkforest]

Hm. We just re-merged audiotags2 into audiotags and there were a lot of changes.

I think these unwraps may be still there - I have to check

Please feel free to send a PR to fix and put some erroring if you find panic'y unwraps