Xcode: Add embed resources support

property: XCODE_EMBED_RESOURCES_PATH after !9008 (merged) merged, should be XCODE_EMBED_RESOURCES usage:

set_target_properties(${target_name} PROPERTIES
                XCODE_EMBED_RESOURCES path/to/build/runtime/shaders
            )

It's useful for game engine sync translated shaders (glslcc) to macos/ios/tvos app bundle Resources folder, showcase: https://github.com/axmolengine/axmol/issues/1279