Add code to infer resource types by their magick numbers rather than having to explicitly provide types at load time #7

There is some code to infer image types when loading Image resources that use the magick number to know which decompression method to use on the image. This code can be generalized to resources, this way we could do without having to explicitly say how we want to load resources, and instead just load them. This may mean replacing the ResourceId and UniqueAnyPtr classes with StringId and std::any respectively.