fix: Inject the faker generator to the OptionalValueResolver (#1187)

Closes #1184.

Author: theofidry

src/Bridge/Symfony/Resources/config/generator/resolver/value.xml

@@ -102,6 +102,7 @@
 
         <service id="nelmio_alice.generator.resolver.value.chainable.optional_value_resolver"
                  class="Nelmio\Alice\Generator\Resolver\Value\Chainable\OptionalValueResolver">
+            <argument type="service" key="$faker" id="nelmio_alice.faker.generator" />
             <tag name="nelmio_alice.generator.resolver.value.chainable_resolver" />
         </service>