fix: SA: Fix many critical rules.

SA stands for Static Analysis.

src/Bundle/ChillMainBundle/Search/SearchApiResult.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Chill\MainBundle\Search;
 
 use Symfony\Component\Serializer\Annotation as Serializer;
@@ -10,6 +12,8 @@ class SearchApiResult
 
     private $result;
 
+    private float $relevance;
+
     public function __construct(float $relevance)
     {
         $this->relevance = $relevance;
@@ -20,7 +24,7 @@ class SearchApiResult
         $this->result = $result;
 
         return $this;
-    } 
+    }
 
     /**
      * @Serializer\Groups({"read"})