Save the filename of the image, video and thumbnail

The draft token interface should save the filename so the artist can find the file that they used in the token. Sometimes file names do not match the title of the art. It is hard to build a large drop of similar looking art without the file name.

When you create the draft token the filename is never shown again.

It is even wiped out when the image is uploaded to ipfs. Sometimes the filename is part of the art and has important information about the practice of the artist.