add failsafe to embed logic to handle the unlikely edge case of embeds loading faster than alpine can react to it

[justinkluever]

we basically mark the iframe as loaded via native javascript so alpine can later pick it up and use that instead for waiting for a potentially never firing load event as it may be already loaded before alpine even initializes.

because of how it works i have limited it to only a few miliseconds after init as we should be safe to assume that either something is broken or the iframe is actually still loading and will fire the event anyway