#13402 test_gcodewriter.cpp add travel_speed_z tests
These tests fail with the legacy implementation of GCodeWriter::travel_to_xyz_force() because it does not decompose the speed into it's components according to the movement unit vector.
#13420 Correct Z speed too high
PrusaSlicer/src/libslic3r/GCodeReader.cpp:24: char Slic3r::get_extrusion_axis_char(const Slic3r::GCodeConfig&): Assertion `axis.size() <= 1' failed.
The set_deserialise_strict() method converts 'A' to the string "65" instead of "A". Perhaps this should be fixed more robustly.
Fix fff_print_tests test name Temeperatures -> Temperatures
Fix fff_print_tests All travel moves happen within skirt
Remove the last travel_moves point which returns to the origin (0,0) which is outside the convex hull. This point was causing CHECK(convex_hull.contains(travel_move)) to fail.
Fix fff_print_tests "Used Filament" test Assertion `std::abs(length) < 1000.0' failed
The test configured a retract_length of 10000000 which is larger than the asserted maximum retraction length of 1000.
PrusaSlicer/src/libslic3r/GCode/GCodeWriter.cpp:473: std::string Slic3r::GCodeWriter::_retract(double, double, std::string_view): Assertion `std::abs(length) < 1000.0' failed.
Fixed by doing the print with two different (legal) retraction lengths and checking that the total_used_filament agrees in both cases.
Fix fff_print_tests "Slicing with retraction and lifting" remove illegal negative restart_extra test case
Negative restart_extra is asserted against at PrusaSlicer/src/libslic3r/Extrucer.cpp:58
How to build - add instructions on how to run the unit tests
