Improve designs for dynamic lookup the source of a block

Due to a recent change in how we are distributing our phishing configuration, we will no longer have access to the _source_ of a block by the time this page is rendered. That is, we won't know whether the site was blocked by our configuration, or by the Phishfort configuration.

We can workaround this problem by dynamically looking up all sets of phishing configuration MetaMask is currently expected to be using, and comparing the blocked site with each one. However this operation would take a few seconds and it might incur substantial hosting costs, so we should not wait on this during the initial page load.

My suggestion would be to lookup this information after the user has clicked the "dispute block" button, so that we route them to the correct page for disputing that block. Alternatively, we could also perform this dynamic lookup when the user clicks "See more information" or something like that.

Start by tracing the warning page's “dispute block” and “See more information” actions. Determine how the dynamic lookup can be deferred until one of those actions, then verify that the result routes the user to the correct dispute page without delaying the initial page load.

Written by the indexing model from the issue text.