setup.py: Register svn_export loader to use through CLI

setup.py

@@ -139,6 +139,7 @@ setup(
     entry_points="""
         [swh.workers]
         loader.svn=swh.loader.svn:register
+        loader.svn-export=swh.loader.svn:register_export
     """,
     classifiers=[
         "Programming Language :: Python :: 3",

swh/loader/svn/__init__.py

-# Copyright (C) 2019-2021  The Software Heritage developers
+# Copyright (C) 2019-2023  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -10,6 +10,15 @@ def register() -> Dict[str, Any]:
     from swh.loader.svn.loader import SvnLoaderFromRemoteDump
 
     return {
-        "task_modules": ["%s.tasks" % __name__],
+        "task_modules": [f"{__name__}.tasks"],
         "loader": SvnLoaderFromRemoteDump,
     }
+
+
+def register_export() -> Dict[str, Any]:
+    from swh.loader.svn.directory import SvnExportLoader
+
+    return {
+        "task_modules": [],
+        "loader": SvnExportLoader,
+    }