build: vendor the Slamtec rplidar SDK in third_party

The repo is now self-contained: driver_rplidar compiles the SDK from
third_party/rplidar_sdk (Linux sources only, teardown delete[] bug fixed
in place), so a plain cmake configure needs no SDK path and no probing —
the XLIDAR_RPLIDAR_SDK_DIR option and external references are gone.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

third_party/rplidar_sdk/src/dataunpacker/dataunnpacker_internal.h

@@ -0,0 +1,74 @@
+/*
+ *  Slamtec LIDAR SDK
+ *
+ *  Copyright (c) 2014 - 2023 Shanghai Slamtec Co., Ltd.
+ *  http://www.slamtec.com
+ *
+ */
+
+ /*
+  *  Sample Data Unpacker System
+  *  Internal Definition
+  */
+
+  /*
+	* 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.
+	*
+	* 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 HOLDER 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.
+	*
+	*/
+
+#pragma once
+
+BEGIN_DATAUNPACKER_NS()
+
+
+class LIDARSampleDataUnpackerInner: public LIDARSampleDataUnpacker
+{
+public:
+	LIDARSampleDataUnpackerInner(LIDARSampleDataListener& l): LIDARSampleDataUnpacker(l){}
+
+	virtual void publishHQNode(_u64 timestamp_uS, const rplidar_response_measurement_node_hq_t* node) = 0;
+	virtual void publishDecodingErrorMsg(int errorType, _u8 ansType, const void* payload, size_t size) = 0;
+	virtual void publishCustomData(_u8 ansType, _u32 customCode, const void* payload, size_t size) = 0;
+	virtual void publishNewScanReset() = 0;
+
+
+	virtual _u64 getCurrentTimestamp_uS() = 0;
+
+};
+
+class IDataUnpackerHandler
+{
+public:
+	IDataUnpackerHandler() {}
+	virtual ~IDataUnpackerHandler() {}
+
+
+	virtual void onUnpackerContextSet(LIDARSampleDataUnpacker::UnpackerContextType type, const void* data, size_t size) = 0;
+
+	virtual _u8 getSampleAnswerType() const = 0;
+	virtual void onData(LIDARSampleDataUnpackerInner* engine, const _u8* data, size_t size) = 0;
+	virtual void reset() = 0;
+
+};
+
+END_DATAUNPACKER_NS()