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/dom/domparser.rs

@@ -90,6 +90,7 @@ impl DOMParserMethods<crate::DomTypeHolder> for DOMParser {
                     false,
                     false,
                     Some(doc.insecure_requests_policy()),
+                    doc.has_trustworthy_ancestor_or_current_origin(),
                     can_gc,
                 );
                 ServoParser::parse_html_document(&document, Some(s), url, can_gc);
@@ -114,6 +115,7 @@ impl DOMParserMethods<crate::DomTypeHolder> for DOMParser {
                     false,
                     false,
                     Some(doc.insecure_requests_policy()),
+                    doc.has_trustworthy_ancestor_or_current_origin(),
                     can_gc,
                 );
                 ServoParser::parse_xml_document(&document, Some(s), url, can_gc);