Check all ancestor navigable trustworthiness for mixed content (#36157)

Propagate through documents a flag that represents if any of the
ancestor navigables has a potentially trustworthy origin.

The "potentially trustworthy origin" concept appears to have gotten
confused in a couple of places and we were instead testing if a URL had
"potentially trustworthy" properties.

The main test for the ancestor navigables is
[mixed-content/nested-iframes](https://github.com/web-platform-tests/wpt/blob/master/mixed-content/nested-iframes.window.js)

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- [X] These changes fix #36108 

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Signed-off-by: Sebastian C <sebsebmc@gmail.com>

components/script/script_thread.rs

@@ -3193,6 +3193,7 @@ impl ScriptThread {
             is_initial_about_blank,
             true,
             incomplete.load_data.inherited_insecure_requests_policy,
+            incomplete.load_data.has_trustworthy_ancestor_origin,
             can_gc,
         );