[nostalgia/studio] Add save action and cleanup

src/nostalgia/studio/lib/editor.cpp

@@ -13,11 +13,21 @@ namespace nostalgia::studio {
 Editor::Editor(QWidget *parent): QWidget(parent) {
 }
 
-void Editor::save() {
+void Editor::saveItem() {
 }
 
 QUndoStack *Editor::undoStack() {
 	return nullptr;
 }
 
+void Editor::save() {
+    save();
+    setUnsavedChanges(false);
+}
+
+void Editor::setUnsavedChanges(bool uc) {
+    m_unsavedChanges = uc;
+    emit unsavedChangesUpdate(uc);
+}
+
 }