[feature request] Add extractor.[manga-extractor].page-reverse functionality

[kattjevfel]

We currently have extractor.[manga-extractor].chapter-reverse, for chapters, but gallery-dl still downloads each chapter starting from page 1. This becomes a problem when used with --abort, since a partial download could then miss out of newer pages.

Thus I am asking for page-reverse to be added, or possibly for it to be integrated into chapter-reverse, whichever you prefer is the best option.

[mikf]

page-reverse option has been added (e69ee41).

I don't think it works for all manga sites due to how they return their results, but I can confirm that it does work for at least mangadex, mangakakalot, and foolslide sites.

Not sure if this actually fixes the underlying problem, though. The fact that gallery-dl handles everything only as individual files might make it impossible to properly fix the underlying issue with the way things are.

[kattjevfel]

Seems to work as intended with mangadex at least, which is all I use anyway. Closing this as I see it as implemented.