[FrameworkBundle] forward error reporting level to insulated Client

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Especially if deprecation notices are silenced on the main php instance, we should also silence them in the insulated Client
You should do the same in `src/Symfony/Component/HttpKernel/Client.php`