Resolved static analysis checks

Author: oojacoboo

src/Propel/Generator/Builder/Om/ObjectBuilder.php

@@ -2627,7 +2627,7 @@ protected function getAccessValueStatement(Column $column): string
         }
 
         if ($column->isPhpBackedEnumType()) {
-            return "\$this->$columnName?->value";
+            return '$this->' . $columnName . '?->value';
         }
 
         return "\$this->$columnName";

src/Propel/Generator/Model/PropelTypes.php

@@ -4,8 +4,10 @@
 
 namespace Propel\Generator\Model;
 
+use BackedEnum;
 use PDO;
 use function in_array;
+use function is_subclass_of;
 use function strtoupper;
 
 /**
@@ -727,7 +729,7 @@ public static function isPhpObjectType(string $phpType): bool
      */
     public static function isPhpBackedEnumType(string $phpType): bool
     {
-        return is_subclass_of($phpType, \BackedEnum::class);
+        return is_subclass_of($phpType, BackedEnum::class);
     }
 
     /**