Impacted versions: 8-11

## Current behavior:

If during an XMLRPC call you try to get anything from `http.request`, you'd get a `RuntimeError` such as this one:

```
Traceback (most recent call last):
  File "/opt/odoo/custom/src/odoo/odoo/service/wsgi_server.py", line 56, in xmlrpc_return
    result = odoo.http.dispatch_rpc(service, method, params)
  File "/opt/odoo/custom/src/odoo/odoo/http.py", line 118, in dispatch_rpc
    result = dispatch(method, params)
  File "/opt/odoo/custom/src/odoo/odoo/service/common.py", line 57, in dispatch
    return g[exp_method_name](*params)
  [...]
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 343, in __getattr__
    return getattr(self._get_current_object(), name)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 302, in _get_current_object
    return self.__local()
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/local.py", line 135, in _lookup
    raise RuntimeError(\'object unbound\')
RuntimeError: object unbound
```

This renders imposible in practice to fix issues such as https://github.com/OCA/server-tools/issues/1125 or to implement https://github.com/odoo/odoo/pull/22212#issuecomment-380425764.

## Expected behavior:

XML-RPC calls should have request, since after all they belong to one. Otherwise, at least there should be an alternate way to access the request parameters.

Fix for v12: https://github.com/odoo/odoo/pull/24187

@Tecnativa
"""
        This method store an action object in the session and returns an integer
        identifying that action. The method get_action() can be used to get
        back the action.
        :param the_action: The action to save in the session.
        :type the_action: anything
        :return: A key identifying the saved action.
        :rtype: integer
        """
        saved_actions = self.setdefault('saved_actions', {"next": 1, "actions": {}})
        
        if len(saved_actions["actions"]) >= 10:
            del saved_actions["actions"][min(saved_actions["actions"])]
        key = saved_actions["next"]
        saved_actions["actions"][key] = action
        saved_actions["next"] = key + 1
        self.modified = True
        return key
    def get_action(self, key):