To improve maintainability, this PR:
1. Rename `web_src/js/modules/aria` to `web_src/js/modules/fomantic`
(the code there are all for aria of fomantic)
2. Move api/transition related code to
`web_src/js/modules/fomantic/api.js` and
`web_src/js/modules/fomantic/transition.js`
No logic is changed.
