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
* https://github.com/FriendsOfSymfony/FOSHttpCacheBundle/pull/152

## TODO
* [x] Implement HTTP cache invalidation
* [x] Make user hash use FOSHttpCache *User Context*
* [x] Tests
and if not the cast will convert it to an array? i mean we have something
```php
$var = (array)'hello';
```
no error or warning will be thrown? just wondering if we don't need the typical 
```php
if ( !is_array( $configuredServers )
{
   $configuredServers = array( $configuredServers )
}
```