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] `./mach build -d` does not report any errors
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- [X] These changes fix #36108 

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---------

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

components/constellation/constellation.rs

@@ -1329,6 +1329,7 @@ where
                     ReferrerPolicy::EmptyString,
                     None,
                     None,
+                    false,
                 );
                 let ctx_id = BrowsingContextId::from(webview_id);
                 let pipeline_id = match self.browsing_contexts.get(&ctx_id) {
@@ -3046,6 +3047,7 @@ where
             ReferrerPolicy::EmptyString,
             None,
             None,
+            false,
         );
         let sandbox = IFrameSandboxState::IFrameUnsandboxed;
         let is_private = false;
@@ -4464,6 +4466,7 @@ where
                     ReferrerPolicy::EmptyString,
                     None,
                     None,
+                    false,
                 );
                 self.load_url_for_webdriver(
                     webview_id,