Fix python generation with nested flatbuffers (#8854)

* implement fix from issue

* implement actual fix

src/idl_gen_python.cpp

diff --git a/src/idl_gen_python.cpp b/src/idl_gen_python.cpp
index d325fee..15b3811 100644
--- a/src/idl_gen_python.cpp
+++ b/src/idl_gen_python.cpp
@@ -1201,12 +1201,15 @@
       return;
     }  // There is no nested flatbuffer.
 
-    const std::string unqualified_name = nested->constant;
+    std::string unqualified_name = nested->constant;
     std::string qualified_name = NestedFlatbufferType(unqualified_name);
     if (qualified_name.empty()) {
       qualified_name = nested->constant;
     }
 
+    // name may be partially qualified -- need to get the true unqualified name
+    unqualified_name = namer_.Denamespace(qualified_name);
+
     const ImportMapEntry import_entry = {qualified_name, unqualified_name};
 
     auto& code = *code_ptr;