* Check errors state on all places of its using (throw exceptions or show a warnings message)
+ To backward compatibility, save "thumbnails_format" value to the config
+ deep_diff() function is extended for the case of "thumbnails" comparison
+ Added unit tests to:
* check a load of configuration for "thumbnails" and "thumbnails_format" options
* check return values for make_and_check_thumbnail_list() function
* Prepared ConfigDefs for placeholders used in EditGCodeDialog.
* Removed unused code and files
* DEBUG mode only: Added check of placeholder's existence in custom_gcode_specific_placeholders and custom_gcode_specific_config_def during the custom G-code parsing.
./src/common/sizer.cpp(2258): assert "CheckSizerFlags(!((flags) & (wxALIGN_CENTRE_VERTICAL)))"
failed in DoInsert(): wxALIGN_CENTRE_VERTICAL will be ignored in this sizer:
wxEXPAND overrides alignment flags in box sizers
* For unsupported languages help link is redirected to the EN page.
+ "uk", "zh" and "ru" languages are removed from current_language_code_safe().
Because those languages aren't supported by Prusa Help.
./src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp:1155:6: warning: ‘void {anonymous}::init_new_text_line(Slic3r::GUI::TextLinesModel&, const Transform3d&, const Slic3r::ModelObject&, Slic3r::GUI::Emboss::StyleManager&)’ defined but not used [-Wunused-function]
../src/slic3r/Utils/EmbossStyleManager.cpp:650:68: warning: ‘depth’ may be used uninitialized in this function [-Wmaybe-uninitialized]
../src/slic3r/GUI/Gizmos/GLGizmoSVG.cpp:1169:17: warning: unused variable ‘data’ [-Wunused-variable]
../src/slic3r/GUI/Gizmos/GLGizmoSVG.hpp:66:159: required from here
Eigen/src/Core/PlainObjectBase.h:751:29: error: invalid cast from type ‘double (*)(const char*) noexcept’ to type ‘Eigen::PlainObjectBase<Eigen::Matrix<double, 2, 1, 2> >::Scalar’ {aka ‘double’}
751 | m_storage.data()[0] = Scalar(val0);
../src/slic3r/GUI/Gizmos/GLGizmoSVG.cpp:888:57: error: no matching function for call to ‘draw_filled(Slic3r::ExPolygons&, std::array<unsigned char, 4>&, std::vector<unsigned char>&, unsigned int&, double&)’
