FilesystemPanel: Replace Extract Apploader/DOL with Extract System Data

Because having one option for each thing to extract is
going to be way too many options once I add support for
more things to extract.

Source/Core/DolphinWX/ISOProperties/FilesystemPanel.h

@@ -32,8 +32,7 @@ private:
     ID_EXTRACT_DIR = 20000,
     ID_EXTRACT_ALL,
     ID_EXTRACT_FILE,
-    ID_EXTRACT_APPLOADER,
-    ID_EXTRACT_DOL,
+    ID_EXTRACT_SYSTEM_DATA,
     ID_CHECK_INTEGRITY,
   };
 
@@ -45,7 +44,7 @@ private:
   void OnRightClickTree(wxTreeEvent&);
   void OnExtractFile(wxCommandEvent&);
   void OnExtractDirectories(wxCommandEvent&);
-  void OnExtractHeaderData(wxCommandEvent&);
+  void OnExtractSystemData(wxCommandEvent&);
   void OnExtractAll(wxCommandEvent&);
   void OnCheckPartitionIntegrity(wxCommandEvent&);