Embed buttons/cards should display current sponsorship status

[UndercoverPervert]

Currently, the embed buttons and cards are effectively static and aren't much better than an image and potentially unusable in places where embedding iframes is not an option, like a forum signature, it would be nice if the "Sponsor" button would update just like the button on profiles to show "Sponsoring" (assuming the viewer is signed in to GitHub).
It'd also be nice if we had a set of images to use similarly to the ones made available by PayPal for areas like forum signatures.