change: preserve search term across different mod providers

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/ui/dialogs/ModDownloadDialog.h

@@ -34,7 +34,7 @@ class PageContainer;
 class QDialogButtonBox;
 class ModrinthModPage;
 
-class ModDownloadDialog : public QDialog, public BasePageProvider
+class ModDownloadDialog final : public QDialog, public BasePageProvider
 {
     Q_OBJECT
 
@@ -58,6 +58,9 @@ public slots:
     void accept() override;
     void reject() override;
 
+private slots:
+    void selectedPageChanged(BasePage* previous, BasePage* selected);
+
 private:
     Ui::ModDownloadDialog *ui = nullptr;
     PageContainer * m_container = nullptr;