Unified: preserve name fallback for accessor resolution

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: hvitved

unified/ql/lib/codeql/unified/internal/dataflow/Content.qll

@@ -104,11 +104,18 @@ class ContentSet extends TContentSet {
 }
 
 module ContentSet {
-  /** Gets resolved field content for `access`, falling back to name-based content. */
+  /**
+   * Gets resolved field content for `access`, falling back to name-based content when resolution
+   * is missing or includes an accessor.
+   */
   ContentSet member(Expr access) {
     result.asSingleton().asField() = T::resolveFieldAccess(access)
     or
-    not exists(T::resolveFieldAccess(access)) and
+    (
+      not exists(T::resolveFieldAccess(access))
+      or
+      exists(T::resolveAccessorAccess(access))
+    ) and
     exists(string name |
       name =
         [