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
odoo/http.py
super(HttpRequest, self).__init__(*args)
        params = collections.OrderedDict(self.httprequest.args)
        params.update(self.httprequest.form)
        params.update(self.httprequest.files)
        params.pop('session_id', None)
        self.params = params
    def _handle_exception(self, exception):
        """Called within an except block to allow converting exceptions
           to abitrary responses. Anything returned (except None) will
           be used as response."""
        try:
            return super(HttpRequest, self)._handle_exception(exception)
        except SessionExpiredException:
            redirect = None
            req = request.httprequest
            if req.method == 'POST':
                request.session.save_request_data()
                redirect = '/web/proxy/post{r.full_path}'.format(r=req)
            elif not request.params.get('noredirect'):
                redirect = req.url
            if redirect:
                query = werkzeug.urls.url_encode({
                    'redirect': redirect,
                })
                return werkzeug.utils.redirect('/web/login?%s' % query)
        except werkzeug.exceptions.HTTPException as e:
            return e
    def dispatch(self):