[Feature] Validate user hasn't forgotten to click 'add' for a link

[BonerFide]

I've noticed that many times I and other users have reported pasting in a link, and forgetting to click 'add' before submitting a studio/scene etc. This is only usually noticed when it was a mandatory link someone else picks up is missing.

Possibly if you have put something in the URL field on the links tab, and you click 'Next' you should get a validation error asking to add the link or remove the link.

Alternatively it could be automatically added on navigate. (You will still get a chance to confirm on the confirm page. I think more people are missing links by not hitting 'add' than would be at risk of accidentally adding an extra link, which is more noticeable than a missing link. This option may not work in cases where the link does not match an regex to select the type of link. (If the stashbox allows arbitrary links that may not be a problem?)

[Jakan-Kink]

As someone who does this probably once a week (if not more), I agree with this request.