feat: PDB import via RawPDB, no msdia140.dll dependency

Replace DIA SDK COM-based PDB importer with RawPDB (MolecularMatters)
which reads PDB files directly via memory-mapped I/O. Adds File menu
"Import PDB..." dialog with type filtering, selection, and progress.

- Vendor raw_pdb into third_party/
- Two-phase API: enumeratePdbTypes() + importPdbSelected()
- Full recursive import of structs/unions/arrays/pointers/bitfields
- PDB import dialog with name filter, select-all, type count
- Benchmark: 1654 types from ntkrnlmp.pdb in 16ms
- Reorganize import/export files into src/imports/

third_party/raw_pdb/src/Examples/Examples_PCH.h

@@ -0,0 +1,53 @@
+// Copyright 2011-2022, Molecular Matters GmbH <office@molecular-matters.com>
+// See LICENSE.txt for licensing details (2-clause BSD License: https://opensource.org/licenses/BSD-2-Clause)
+
+#pragma once
+
+#include "Foundation/PDB_Warnings.h"
+
+// The following clang warnings must be disabled for the examples to build with 0 warnings
+#if PDB_COMPILER_CLANG
+#	pragma clang diagnostic ignored "-Wformat-nonliteral" 	// format string is not a string literal
+#	pragma clang diagnostic ignored "-Wswitch-default" 		// switch' missing 'default' label
+#   pragma clang diagnostic ignored "-Wcast-align"		 	// increases required alignment from X to Y
+#   pragma clang diagnostic ignored "-Wold-style-cast" 		// use of old-style cast
+#endif
+
+#if PDB_COMPILER_MSVC
+#	pragma warning(push, 0)
+#elif PDB_COMPILER_CLANG
+#	pragma clang diagnostic push
+#endif
+
+#if PDB_COMPILER_MSVC
+	// we compile without exceptions
+#	define _ALLOW_RTCc_IN_STL
+
+	// triggered by Windows.h
+#	pragma warning (disable : 4668)
+
+	// triggered by xlocale in VS 2017
+#	pragma warning (disable : 4625)		// copy constructor was implicitly defined as deleted
+#	pragma warning (disable : 4626)		// assignment operator was implicitly defined as deleted
+#	pragma warning (disable : 5026)		// move constructor was implicitly defined as deleted
+#	pragma warning (disable : 5027)		// move assignment operator was implicitly defined as deleted
+#	pragma warning (disable : 4774)		// format string expected in argument 1 is not a string literal
+#endif
+
+#ifdef _WIN32
+#	define NOMINMAX
+#	include <Windows.h>
+#	undef cdecl
+#endif
+#	include <vector>
+#	include <unordered_set>
+#	include <chrono>
+#	include <string>
+#	include <algorithm>
+#	include <cstdarg>
+
+#if PDB_COMPILER_MSVC
+#	pragma warning(pop)
+#elif PDB_COMPILER_CLANG
+#	pragma clang diagnostic pop
+#endif