Move routes stubs to @python2 directory (#5637)

* Move routes stubs to @python2 directory

* Ignore Python-2-only stubs for stubtest

* Use standard idiom for re-exporting items

Co-authored-by: Akuli <akuviljanen17@gmail.com>

pyrightconfig.stricter.json

@@ -16,7 +16,6 @@
         "stubs/openssl-python",
         "stubs/pathlib2",
         "stubs/pymssql",
-        "stubs/Routes",
         "stubs/scribe",
         "stubs/tornado",
         // Modules that are incomplete in some way.