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
"id": null}
      <-- {"jsonrpc": "2.0",
           "result": { "res1": "val1" },
           "id": null}
    Request producing a error::
      --> {"jsonrpc": "2.0",
           "method": "call",
           "params": {"context": {},
                      "arg1": "val1" },
           "id": null}
      <-- {"jsonrpc": "2.0",
           "error": {"code": 1,
                     "message": "End user error message.",
                     "data": {"code": "codestring",
                              "debug": "traceback" } },
           "id": null}
    """
    _request_type = "json"
    def __init__(self, *args):
        super(JsonRequest, self).__init__(*args)
        self.jsonp_handler = None
        args = self.httprequest.args
        jsonp = args.get('jsonp')
        self.jsonp = jsonp
        request = None
        request_id = args.get('id')
        
        if jsonp and self.httprequest.method == 'POST':
            
            def handler():