Remove redirect requirement by performing ajax request from wishlist page.

Also:
Move button to next to Store Page visit, as it is not external page.
Disable button if added and set wishlisted in session storage.
If session storage has the item as wishlisted, do not show button
Fix add_empty_wishlist_button functions and merge
Restyle empty buttons.
Change default spamcommentregex due to Steam emoticon hearts, etc.