[CAL-3929] Embed: Open success page in the `top` and not in the `parent`

[hariombalhara]

Open success page in top instead of parent. It mostly does the same thing unless embed is inside another iframe on the webpage which restricts navigation(in which case top.location.href works but not parent.location.href)

More details in private link about the user who reported it https://app.campsite.co/cal/posts/1giz24q8pif8

_{From SyncLinear.com | CAL-3929}

[hariombalhara]

Adding it to v4.3 as one more user reported this and it completely breaks the booking.