- Field mapper is now removed from Adapters and set into it's own object

- Added a PK to Column (IS)

src/Adapter/SqlAdapterInterface.php

@@ -4,6 +4,6 @@ namespace Ulmus\Adapter;
 
 interface SqlAdapterInterface
 {
-    public function escapeIdentifier(string $segment, int $type) : string;
+    public static function escapeIdentifier(string $segment, int $type) : string;
     public function defaultEngine() : ? string;
 }