Remove mimalloc from 3rdparty and use it as external dependence

Have a simple example header Allocator.h for using and testing mimalloc

Author: xarray

3rdparty/CMakeLists.txt

@@ -489,9 +489,8 @@ SET(LIBRARY_FILES
 	tiny_obj_loader.h tiny_gltf.h picojson.h nanoflann.hpp exprtk.hpp mio.hpp any.hpp VHACD.h
     backward.hpp strtk.hpp ghc/filesystem.hpp rapidxml/rapidxml.hpp rapidjson/rapidjson.h
     nanoid/nanoid.cpp nanoid/nanoid.h nanoid/crypto_random.cpp nanoid/crypto_random.h
-    sqlite3.c sqlite3.h ofbx.cpp ofbx.h miniz.h tinyexr.h dkm_parallel.hpp
+    sqlite3.c sqlite3.h ofbx.cpp ofbx.h miniz.h tinyexr.h dkm_parallel.hpp lsqcpp.hpp
     mikktspace.c mikktspace.h laplacian_deformation.cpp laplacian_deformation.hpp
-	mimalloc/static.c mimalloc/mimalloc.h mimalloc/mimalloc-new-delete.h lsqcpp.hpp
 	lightmapper.h xatlas.cpp xatlas.h mapbox/variant.hpp mapbox/geometry.hpp mapbox/polylabel.hpp
     GL/glew.c GL/glew.h xxYUV/rgb2yuv.cpp xxYUV/yuv2rgb.cpp xxYUV/cpu.cpp timeout.c timeout.h
     BSplineFitting/cubic_b_spline.cpp BSplineFitting/open_cubic_b_spline.cpp BSplineFitting/spline_curve_fitting.cpp