Add OpenVDB (and sub libraries) the new way

deps/OpenEXR/OpenEXR.cmake

@@ -0,0 +1,15 @@
+prusaslicer_add_cmake_project(OpenEXR
+    GIT_REPOSITORY https://github.com/openexr/openexr.git
+    DEPENDS ${ZLIB_PKG}
+    GIT_TAG eae0e337c9f5117e78114fd05f7a415819df413a #v2.4.0
+    CMAKE_ARGS
+        -DCMAKE_POSITION_INDEPENDENT_CODE=ON
+        -DBUILD_TESTING=OFF 
+        -DPYILMBASE_ENABLE:BOOL=OFF 
+        -DOPENEXR_VIEWERS_ENABLE:BOOL=OFF
+        -DOPENEXR_BUILD_UTILS:BOOL=OFF
+)
+
+if (MSVC)
+    add_debug_dep(dep_OpenEXR)
+endif ()