Fix Croatian localedata issues in mastodon.js (#2844)

* locale: added hr and oc react-intl locale data

* adds Croatian locale data in mastodon.js
* adds Occitan locale data in mastodon.js

Resolves #2667

* locale: sort locale data imports in mastodon.js

* locale: remove oc reference

* [react-intl](https://github.com/yahoo/react-intl) does not provide
  default locale data for Occitan. Hence removed from reference.