Added a project specific config to the PresetBundle class.

This project specific config will be stored into the config.ini,
into .3mf and .amf and .gcode,
and recover it from the same files.

xs/xsp/GUI_Preset.xsp

@@ -161,6 +161,8 @@ PresetCollection::arrayref()
     Ref<PresetCollection>       print()    %code%{ RETVAL = &THIS->prints;   %};
     Ref<PresetCollection>       filament() %code%{ RETVAL = &THIS->filaments; %};
     Ref<PresetCollection>       printer()  %code%{ RETVAL = &THIS->printers;  %};
+    Ref<DynamicPrintConfig>     project_config() %code%{ RETVAL = &THIS->project_config; %};
+
     bool                        has_defauls_only();
 
     std::vector<std::string>    filament_presets() %code%{ RETVAL = THIS->filament_presets; %};