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
"""
        Authenticate the current user with the given db, login and
        password. If successful, store the authentication parameters in the
        current session and request.
        :param uid: If not None, that user id will be used instead the login
                    to authenticate the user.
        """
        if uid is None:
            wsgienv = request.httprequest.environ
            env = dict(
                base_location=request.httprequest.url_root.rstrip('/'),
                HTTP_HOST=wsgienv['HTTP_HOST'],
                REMOTE_ADDR=wsgienv['REMOTE_ADDR'],
            )
            uid = dispatch_rpc('common', 'authenticate', [db, login, password, env])
        else:
            security.check(db, uid, password)
        self.db = db
        self.uid = uid
        self.login = login
        self.session_token = uid and security.compute_session_token(self)
        request.uid = uid
        request.disable_db = False
        if uid: self.get_context()
        return uid
    def check_security(self):