Add parameter type declarations to contracts.

Author: derrabus

Tests/DependencyInjection/Compiler/DataCollectorTranslatorPassTest.php

@@ -108,7 +108,7 @@ public function getNotImplementingTranslatorBagInterfaceTranslatorClassNames()
 
 class TranslatorWithTranslatorBag implements TranslatorInterface
 {
-    public function trans($id, array $parameters = [], $domain = null, $locale = null): string
+    public function trans(string $id, array $parameters = [], string $domain = null, string $locale = null): string
     {
     }
 }