qdoc: Do not prefix related non-members with a parent scope

The fact that a related non-member has a parent-child relationship
with the node it relates to is simply an implementation detail in
QDoc - it should not be visible in the generated output.

The same applies for proxy nodes - i.e. aggregates that hold
children documented in another module.

Fixes: QTBUG-77960
Change-Id: I8d83ee7022d5f15af720cbd65c138be0469d39a0
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Martin Smith <martin.smith@qt.io>

src/qdoc/cppcodemarker.cpp

@@ -130,8 +130,13 @@ QString CppCodeMarker::markedUpSynopsis(const Node *node,
     name = "<@name>" + name + "</@name>";
 
     if (style == Section::Details) {
-        if (!node->parent()->name().isEmpty() && !node->parent()->isHeader() &&
-            !node->isProperty() && !node->isQmlNode() && !node->isJsNode())
+        if (!node->isRelatedNonmember() &&
+            !node->isProxyNode() &&
+            !node->parent()->name().isEmpty() &&
+            !node->parent()->isHeader() &&
+            !node->isProperty() &&
+            !node->isQmlNode() &&
+            !node->isJsNode())
             name.prepend(taggedNode(node->parent()) + "::");
     }