Feature Request - Discard .img(/.sub) files when using GD mode.

[ehw]

Is your feature request related to a problem? Please describe.
Is outputting a .img and maybe even the .sub necessary for using the GD command? It seems like a lot of wasted space since I don't think anything Dreamcast related needs high density tracks specifically in CloneCD format. Because no .ccd is output in GD mode, this kinda makes the .img and .sub a bit useless?

I'm not entirely sure about the .sub file. It's never been considered before and it doesn't look like it will be any time soon.

Describe the solution you'd like
When GD is run, just don't output .img, and .sub. This way we only have the .scm file, and the individual .bins that make up the tracks.

Additional context
This isn't really important. I'm just curious if any of it is necessary or not.