Check unsaved changes (#6991)

* Check Unsaved changes (partially related to #5903)
 + Allow create new project when Plater is empty, but some of presets are modified (related to #5903)
 + When creating new project allow Keep or Discard modification from previous project
 + Added check of changes:
    * before any load project (including DnD and "Load From Recent Projects")
    * before preset updater
    * when configuration is changing from the ConfigWizard
 + Dialog caption is added for each check

 + Create/Destroy ConfigWizard every time when it's called

* Check Unsaved changes: Next Improvements
 + For dialog "Save project changes" added a reason of saving and name of the current project (or "Untitled")
 + UnsavedChangesDialog: Headers are extended to better explain the reason
 + Preferences: Fixed tooltiops for "Always ask for unsaved changes when..."
 + Suppress "Remember my choice" checkbox for actions which are not frequently used

* Fixed behavior of the application when try to save changed project but "Cancel" button is selected in "Save file as..." dialog

* Check unsaved changes: Improvements for Config Wizard - Check all cases when presets should be updated
 + Fixed info line for Materials pages. Text of the info relates to the printer technology now

* Improved suggested name for a project when Application is closing

* Fixed Linux/OSX build warnings

src/slic3r/GUI/MainFrame.hpp

@@ -190,7 +190,7 @@ public:
     bool can_save() const;
     bool can_save_as() const;
     void save_project();
-    void save_project_as(const wxString& filename = wxString());
+    bool save_project_as(const wxString& filename = wxString());
 
     void        add_to_recent_projects(const wxString& filename);
     void        technology_changed();