Add Missing Includes Across src/libslic3r

Every libslic3r source and header now directly includes the headers declaring what it uses, rather than relying on the precompiled header or transitive includes. Generated with clang-tidy misc-include-cleaner, with libslic3r headers spelled libslic3r/... so they resolve outside the library's private include paths. MultiMaterialSegmentation.hpp, Support/SupportParameters.hpp and Format/STEP.hpp are made self-contained by hand.

src/libslic3r/Emboss.cpp

@@ -1,12 +1,35 @@
+#include <cmath>
+#include <cassert>
+#include <algorithm>
+#include <functional>
+#include <iterator>
+#include <cstdint>
+#include <memory>
+#include <cstdio>
+#include <cctype>
+#include <limits>
+#include <math.h>
+#include <Eigen/Geometry>
+#include <Eigen/Core>
 #include <numeric>
 #include "Emboss.hpp"
+#include <optional>
 #include <stdio.h>
 #include <numeric>
 #include <cstdlib>
 #include <boost/nowide/convert.hpp>
 #include <boost/log/trivial.hpp>
 #include <ClipperUtils.hpp> // union_ex + for boldness(polygon extend(offset))
+#include "ExPolygon.hpp"
+#include <vector>
+#include "AABBTreeIndirect.hpp"
+#include <utility>
+#include "EmbossShape.hpp"
+#include <string>
 #include "IntersectionPoints.hpp"
+#include "Polygon.hpp"
+#include "TextConfiguration.hpp"
+#include "Point.hpp"
 
 #define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
 #include "imgui/imstb_truetype.h" // stbtt_fontinfo