Adding URL to metadata

[thatfuckingbird]

Currently some extractors write post and file URLs to the metadata dict, while others do not.
It would be useful to always at least add the file URL to the metadata (post URL I'm not sure can be done universally, so maybe best left to the extractors). This should be easy to implement, since the metadata dict and the corresponding URL is yielded at the same time from extractors.

There is the question of what should be the name of the key in the metadata dict for this URL? (Can't be url or file_url as it could clash with some existing usage, so maybe gallerydl_file_url or something, not sure...).

What do you think, @mikf ?

[mikf]

Took a while, but I've added a url-metadata option that let's you specify the name of the metadata field that should contain the download URL. For example "url-metadata": "gallerydl_file_url"would put them as gallerydl_file_url.

I do at some point want to redo the way extractors return their results and change the current yield Message.***, url, kwdict to just yielding a dict with metadata and URL combined, where a URL is always named url. That's why the results for some sites already have a url field.

[thatfuckingbird]

Thank you! I wouldn't mind it always being url either, but for now this is great.