Configure icons in the Release page

Allow the admin or product owner to configure what FontAwesome icons to show in the Release module.

It can be in general (to be a setting of the Talk module of the product. So it applies as default for all entries in the talk page. There shall be a setting for two icons (one for the title and other for the timeline) for both Releases and Announcements.

And it can be specifically defined for each item (overwriting the default icons).