DialogButtons fixes and apply to more windows (#9809)

* step import dialog

* update

* update

* drop file dialog

* Update UnsavedChangesDialog.cpp

* update

* fix focus

* Update CreatePresetsDialog.cpp

* improve usage of return button

* fix first button not getting hover effects

* update

* update

* improve button styles

* update button events

* update button events

* update button events

* remove Raise()

src/slic3r/GUI/StepMeshDialog.hpp

@@ -35,8 +35,6 @@ public:
     }
 private:
     Slic3r::Step& m_file;
-    Button* m_button_ok = nullptr;
-    Button* m_button_cancel = nullptr;
     wxCheckBox* m_checkbox = nullptr;
     wxCheckBox* m_split_compound_checkbox = nullptr;
     wxString m_linear_last;