feat: CARLA build support for Unreal Editor dependency, OBJ loader, Blender normalization and calibration

[im-hashim]

Summary

Extends the vehicle import pipeline with full-stack CARLA/Unreal build support, a hardened mesh pipeline, and Blender integration.

Build

• Full-stack build path: CARLA_DIR + UNREAL_DIR now wire through CMake to produce a build that includes UnrealEditor support alongside the standalone Studio binary
• Absolute path resolution for CARLA_DIR/UNREAL_DIR in Makefile to prevent relative-path issues when invoking from outside the repo root
• libcarla headers brought to C++17 compliance
• Fixed all implicit qsizetype → int and qint64 → implicit conversions across vehicle import files (carla_spawn.cpp, editor_process.cpp, importer_client.cpp, mesh_aabb.cpp)
• Fixed deprecated [=] lambda captures capturing this implicitly (C++20) — updated to [=, this] throughout vehicle_import_page.cpp
• Added missing standard and Qt includes across the vehicle import module
• Moved view_gizmo.h include under its CARLA_STUDIO_WITH_QT3D guard; added missing stub implementations for the non-Qt3D path

Mesh pipeline

• Robust OBJ loader: handles degenerate faces, negative indices, and missing UV/normal data without crashing
• Smooth normals from Blender exports are preserved and forwarded correctly through the import pipeline
• Mesh diagnostics: reports vertex count, face count, malformed faces, and AABB per imported asset

Blender integration

• blender_calibration: drives a Blender subprocess to apply wheel positions, suspension geometry, and axle offsets exported from Studio directly back into the source .blend file

Test runner

• Stripped --update-documentation from argv before passing to QTest::qExec — QTest rejects unknown flags, which was causing make test to fail when that flag was present