Move test applications to src/apps/

The cam and qcam test application share code, currently through a crude
hack that references the cam source files directly from the qcam
meson.build file. To prepare for the introduction of hosting that code
in a static library, move all applications to src/apps/.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/apps/qcam/message_handler.cpp

@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020, Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * message_handler.cpp - qcam - Log message handling
+ */
+
+#include "message_handler.h"
+
+QtMessageHandler MessageHandler::handler_ = nullptr;
+bool MessageHandler::verbose_ = false;
+
+MessageHandler::MessageHandler(bool verbose)
+{
+	verbose_ = verbose;
+	handler_ = qInstallMessageHandler(&MessageHandler::handleMessage);
+}
+
+void MessageHandler::handleMessage(QtMsgType type,
+				   const QMessageLogContext &context,
+				   const QString &msg)
+{
+	if (type == QtDebugMsg && !verbose_)
+		return;
+
+	handler_(type, context, msg);
+}