Add asset loading support.

tools/copytool/CMakeLists.txt

@@ -0,0 +1,11 @@
+# Copyright (c) 2023 Dominic Msters
+# 
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+function(tool_copy target input output)
+  add_custom_target(${target}
+    COMMAND ${CMAKE_COMMAND} -E copy ${input} ${output}
+  )
+  add_dependencies(dawnassets ${target})
+endfunction()