HotkeyInputConfigDialog: Move UI creation into named functions

The constructor shouldn't be used as a dumping ground for all UI-related
initialization. Doing so makes it somewhat more difficult to reason about
how certain UI elements get created. It also puts unrelated identifiers in
the same scope.

This separates the UI creation out so code relevant to each component
is self-contained.

Source/Core/DolphinWX/Input/HotkeyInputConfigDiag.h

@@ -6,9 +6,31 @@
 
 #include "DolphinWX/Input/InputConfigDiag.h"
 
+class wxBoxSizer;
+class wxNotebook;
+class wxPanel;
+
 class HotkeyInputConfigDialog final : public InputConfigDialog
 {
 public:
   HotkeyInputConfigDialog(wxWindow* parent, InputConfig& config, const wxString& name,
                           bool using_debugger, int port_num = 0);
+
+private:
+  wxBoxSizer* CreateMainSizer();
+  wxBoxSizer* CreateDeviceRelatedSizer();
+  wxBoxSizer* CreateDeviceProfileSizer();
+
+  void InitializeNotebook();
+  wxPanel* CreateGeneralPanel();
+  wxPanel* CreateTASToolsPanel();
+  wxPanel* CreateDebuggingPanel();
+  wxPanel* CreateWiiPanel();
+  wxPanel* CreateGraphicsPanel();
+  wxPanel* CreateStereoscopic3DPanel();
+  wxPanel* CreateSaveAndLoadStatePanel();
+  wxPanel* CreateOtherStateManagementPanel();
+
+  wxNotebook* m_notebook;
+  bool m_using_debugger;
 };