If you are talking about things like styled text, where you drag an image on to the page directly then that option does kind of exist already in RW8.
I don’t recommend doing it this way.
If you set the advanced option for Site Resources to “Leave in place”
Now if you drag an image onto a page RW8 will put that image into the Resources tray.
So open Resources and find the image, right click and you will have an option to Reveal in Finder.
That would take you to the original image, assuming it’s still there. That’s exactly why I don’t recommend it (and it’s not the default). If the image gets moved, deleted, or renamed the project will not find it and it will be broken.
If you have the Site Resouces option in advanced settings set to “Copy into document”(the default) it will NOT be a compressed copy. Whatever you dragged onto the page will be what is stored in the project file resources and what will end up on the website.