PX4 ROS2 msg conformity and explicit topics

- .msg files are PascalCase
 - topics are still either per msg or explicitly listed in TOPICS
 - compatible structs are still generated (eg struct msg_s), but ROS2 style px4::msg::Msg is also available

uORBTopics.cpp.in

@@ -0,0 +1,56 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2021 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include <uORB/uORB.h>
+
+#include "uORBTopics.hpp"
+
+@PX4_ORB_DEFINE_STR@
+
+const constexpr struct orb_metadata *const uorb_topics_list[ORB_TOPICS_COUNT] = {
+@PX4_MSG_TOPIC_ORB_ID@
+};
+
+const struct orb_metadata *const *orb_get_topics()
+{
+	return uorb_topics_list;
+}
+
+const struct orb_metadata *get_orb_meta(ORB_ID id)
+{
+	if (id == ORB_ID::INVALID) {
+		return nullptr;
+	}
+
+	return uorb_topics_list[static_cast<uint8_t>(id)];
+}