[Swift] Object API support (#5826)

* Adds Object-api support to swift

* Fixed indentation issues

* Removed indentation within namespaces

include/flatbuffers/code_generators.h

@@ -75,6 +75,10 @@ class CodeWriter {
   void DecrementIdentLevel() {
     if (cur_ident_lvl_) cur_ident_lvl_--;
   }
+    
+  void SetPadding(const std::string &padding) {
+    pad_ = padding;
+  }
 
  private:
   std::map<std::string, std::string> value_map_;