Support grabbing the full image for Tinami uploads, rather than the sample.
Getting the full image requires making a request like this:
curl -X POST \
-H 'Referer: https://www.tinami.com/' \
-H 'Content-Type: application/x-www-form-urlencoded' \
-H 'Cookie: Tinami2SESSID=<redacted>;' \
--data-raw 'action_view_original=true&cont_id=1087268ðna_csrf=<redacted>' \
https://www.tinami.com/view/1087268
Then scraping the <img> tag from the resulting HTML page.
If the post has multiple images, then we need to scrape and pass the
`sub_id` of the image too.
Fixes#2818.
