Fix EZP-22318: Make Symfony session options SiteAccess aware

https://jira.ez.no/browse/EZP-22318

This patch allows to override session options at the SiteAccess level.

This includes:
* cookie_domain
* cookie_path
* cookie_lifetime
* cookie_secure
* cookie_httponly

Additionally, `session_name` setting is deprecated in favor of `session.name`:

Before:
```yaml
ezpublish:
    system:
        my_siteaccess:
            session_name: SomeSessionName
```

After:
```yaml
ezpublish:
    system:
        my_siteaccess:
            session:
                name: SomeSessionName
                cookie_path: /my_siteaccess
                cookie_httponly: true
```

## TODO
* [x] Allow to override session options
* [x] Fix side effect with fragment framework when using ESIs / Hincludes
* [ ] Fix tests and add even more