Fix EZP-22400: Use FOSHttpCacheBundle

> https://jira.ez.no/browse/EZP-22400

This PR adds support of FOSHttpCacheBundle and replaces eZ custom logic by FOSHttpCache

Depends on:
* https://github.com/FriendsOfSymfony/FOSHttpCache/pull/128 (merged)
* https://github.com/FriendsOfSymfony/FOSHttpCacheBundle/pull/152

## TODO
* [x] Implement HTTP cache invalidation
* [x] Make user hash use FOSHttpCache *User Context*
* [x] Tests
Welln the 2.x branches are not maintained anymore in the bundle, so it is fine to depend on 3.0 IMO (we fixed the compatibility with Symfony 2.3 in the 3.0.2 release of the bundle, to avoid having to bring 2.x in maintained mode again)