[IMPROVEMENT] Optimisation for prerendered pages

[dianafulga]

For the moment we won't execute the content script when the browser prerenders the pages before the user actually navigates to them. This was implemented with #477

For optimisation we want to save the details of the links when a page is prerendered, so that when actually navigating to the page, the payments are done much faster. Started working on this in this PR .
For this approach, we need to:

• clear the preloaded urls, that are not used, because the user changes the url

[sidvishnoi]

Also see: https://developer.mozilla.org/en-US/docs/Web/API/Speculation_Rules_API