Update test infrastructure to use register_actions hook

- Consolidated register_permissions and register_actions hooks in my_plugin.py
- Added permission_resources_sql hook to provide SQL-based permission rules
- Updated conftest.py to reference datasette.actions instead of datasette.permissions
- Updated fixtures.py to include permission_resources_sql hook and remove register_permissions
- Added backwards compatibility support for old datasette-register-permissions config
- Converted test actions (this_is_allowed, this_is_denied, etc.) to use permission_resources_sql

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/fixtures.py

@@ -45,13 +45,13 @@ EXPECTED_PLUGINS = [
             "homepage_actions",
             "menu_links",
             "permission_allowed",
+            "permission_resources_sql",
             "prepare_connection",
             "prepare_jinja2_environment",
             "query_actions",
             "register_actions",
             "register_facet_classes",
             "register_magic_parameters",
-            "register_permissions",
             "register_routes",
             "render_cell",
             "row_actions",