Reorganize key names for Likes
Reorganize key names for Likes

See [flarum/core #265](https://github.com/flarum/core/issues/265).

- Adjusts key names to three-tier namespacing.
- Adds newly extracted strings.
- Adds commenting to match core.
- Adds a comment to indicate a pluralizable string.
- Supports https://github.com/flarum/likes/pull/3.

FlarumChina/flarum-ext-simplified-chinese-pro,balkanje/flarum-ext-bosnian1,FlarumChina/flarum-ext-simplified-chinese-pro,raweba/flarum-ext-danish,flarum/english,ogioncz/flarum-ext-czech,ogioncz/flarum-ext-czech,pladask/flarum-ext-norwegian-bokmal,pladask/flarum-ext-norwegian-nynorsk,gtugablue/flarum-ext-portuguese,pladask/flarum-ext-norwegian-nynorsk,pladask/flarum-ext-norwegian-bokmal,flarum/flarum-ext-english