Add Missing Includes Across the Remaining Sources and Tests (#16071)

* Ignore Clipper, libpng, mcut and Boost.Polygon Internals in clang-tidy

Each only works through a wrapper or umbrella header: libslic3r/clipper.hpp or clipper_z.hpp configure Clipper before including it, png.h pulls in libpng's config headers, and Boost.Polygon's headers only compile through polygon.hpp or voronoi.hpp.

* Ignore minilzo's Config Headers in clang-tidy

lzoconf.h and lzodefs.h are internal to minilzo.h, which is what the code includes.

* Add Missing Includes Across the Remaining Sources and Tests

Covers src/slic3r/Utils, src/slic3r/plugin, src/slic3r/Config, src/libvgcode, src/dev-utils, src/OrcaSlicer.cpp and tests/, the directories left after src/slic3r/GUI and src/libslic3r. Generated with clang-tidy misc-include-cleaner. libvgcode's own headers are included by relative path as in the rest of that library, and Catch2 and pybind11 with angle brackets as elsewhere in the repo.

* Make the GUI and Test Headers Compile on Their Own

Each now includes, or forward-declares, what it uses instead of relying on what its includers happened to include first. Headers that only compile on one platform, or that nothing built includes, are left alone.

* Keep Windows and nanosvg Setup Ahead of the Added Includes

OrcaSlicer.cpp and several tests set _WIN32_WINNT, WIN32_LEAN_AND_MEAN or NOMINMAX before including Windows.h, and the profile validator defines NANOSVG_IMPLEMENTATION before any libslic3r header. The added includes had landed above those blocks, which broke the Windows build.

* Add the GUI Includes the First Pass Missed

Covers headers that only became editable once they compiled on their own, and wx symbols whose suggested header changed as the clang-tidy ignore list grew after the src/slic3r/GUI pass.

* Keep the Added Test Includes Below the NOMINMAX Guard

test_marchingsquares.cpp and test_texture_displacement.cpp had includes inside #ifndef NOMINMAX, which the tests inherit as defined on Windows from libslic3r, so those were skipped there. .clang-tidy also ignores the MSVC STL and UCRT internals, Boost.Multiprecision's fwd.hpp and CPython's Windows include directory, as in #16068.

tests/libslic3r/test_utils.cpp

@@ -1,5 +1,14 @@
+#include <boost/filesystem/path.hpp>
+#include <boost/filesystem/directory.hpp>
+#include <boost/filesystem/operations.hpp>
+#include <boost/filesystem/file_status.hpp>
 #include <catch2/catch_all.hpp>
 
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/matchers/catch_matchers.hpp>
+#include <catch2/matchers/catch_matchers_string.hpp>
+#include <catch2/generators/catch_generators.hpp>
+#include <catch2/catch_message.hpp>
 #include "libslic3r/Utils.hpp"
 
 #include "test_utils.hpp"
@@ -8,10 +17,14 @@
 
 #include <algorithm>
 #include <cctype>
+#include <cstddef>
 #include <fstream>
+#include <ios>
+#include <iterator>
 #include <string>
 #include <thread>
 #include <system_error>
+#include <utility>
 
 #ifndef _WIN32
 #include <unistd.h>     // getuid