[Feature Request] ARB support for localization

[saurabhkumar8112]

Thanks for the package
ARB is a popular format for maintaining localization dictionary file. As far as I could see easy_localization doesn't support .arb files. It does however supports .json(nested), .xml and .yaml.

ARB is supported by intl as well. Many CI tools for localization are supporting ARB now. I think it would be nice if easy_localization also support ARB format.

There's already a similar feature request made in 2020 but i thought its too old so I made a new one