add rpc addon and fix 19.0 compatibility issues

- add missing rpc addon (auto_install, required by server_wide_modules)
- add __init__.py -> init.py symlink for odoo package importability
- re-export image_process from odoo.tools (needed by web_editor)
- add backward-compatible slug/unslug functions in http_routing

🤖 assisted by claude

odoo-bringout-oca-ocb-rpc/rpc/controllers/jsonrpc.py

@@ -0,0 +1,16 @@
+import logging
+
+from odoo.http import Controller, dispatch_rpc, route
+
+from . import RPC_DEPRECATION_NOTICE, _check_request
+
+logger = logging.getLogger(__name__)
+
+
+class JSONRPC(Controller):
+    @route('/jsonrpc', type='jsonrpc', auth="none", save_session=False)
+    def jsonrpc(self, service, method, args):
+        """ Method used by client APIs to contact OpenERP. """
+        logger.warning(RPC_DEPRECATION_NOTICE, __name__)
+        _check_request()
+        return dispatch_rpc(service, method, args)