Create SQL data source utils class

- Extract logic used in SQLite and MySQL for logging and closing SQL objects
    - Decided to leave buildAuthFromResultSet methods individually as this might be more implementation-specific
- Rename DataSource#close to DataSource#closeConnection to fix conflict with static import

src/main/java/fr/xephi/authme/initialization/TaskCloser.java

@@ -70,7 +70,7 @@ public class TaskCloser implements Runnable {
         }
 
         if (dataSource != null) {
-            dataSource.close();
+            dataSource.closeConnection();
         }
     }