Renders the Follow buttons of a user's profile and of a playlist's page.
Both go through FollowContext, which follows at once and rolls back when
the request fails; the button then says so beside it.
Renders the button that follows or unfollows a playlist. It renders nothing
for a visitor or a private playlist, and is disabled until the follows have
loaded. Unlike FollowUserButton, it shows on the user's own
playlists too.
Renders the button that follows or unfollows a user. It renders nothing for
a visitor or on the user's own profile, and is disabled until the follows
have loaded.