Qt: Initial CPU debugger widget implementation

Co-Authored-By: liuk707 <62625900+liuk7071@users.noreply.github.com>

include/panda_qt/disabled_widget_overlay.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <QtWidgets>
+
+class DisabledWidgetOverlay : public QWidget {
+	Q_OBJECT
+
+  public:
+	DisabledWidgetOverlay(QWidget *parent = nullptr, QString overlayText = tr("This widget is disabled")) : text(overlayText), QWidget(parent) {
+		setVisible(false);
+	}
+
+  private:
+	QString text;
+
+	void paintEvent(QPaintEvent *) override {
+		QPainter painter = QPainter(this);
+		painter.fillRect(rect(), QColor(60, 60, 60, 128));
+		painter.setPen(Qt::gray);
+
+		QFont font = painter.font();
+		font.setBold(true);
+		font.setPointSize(18);
+
+		painter.setFont(font);
+		painter.drawText(rect(), Qt::AlignCenter, text);
+	}
+};