Migrating more signal/slot connects to modern system.

openTitleBlockTemplate needs a lambda: its matching overload has a default bool argument, so its pointer-to-member type
requires two parameters regardless of the default, while the signal provides only one -- no cast alone can both resolve the overload and
connect to a single-argument signal.

setAutoNum(QString)/setAutoNum(int,int) is a sender-side signal overload which needed a qOverload<QString> to match setFolioAutonum's
single-argument slot.

sources/elementspanelwidget.cpp

@@ -120,9 +120,9 @@ ElementsPanelWidget::ElementsPanelWidget(QWidget *parent) : QWidget(parent) {
 	connect(elements_panel, &ElementsPanel::customContextMenuRequested, this, &ElementsPanelWidget::handleContextMenu);
 	connect(
 		elements_panel,
-		SIGNAL(requestForTitleBlockTemplate(const TitleBlockTemplateLocation &)),
+		&ElementsPanel::requestForTitleBlockTemplate,
 		QETApp::instance(),
-		SLOT(openTitleBlockTemplate(const TitleBlockTemplateLocation &))
+		[app = QETApp::instance()](const TitleBlockTemplateLocation &location) { app->openTitleBlockTemplate(location); }
 	);
 
 		// manage double click on TreeWidgetItem