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
subclasses = list(unique(c for c in get_subclasses(cls) if c is not cls))
            if subclasses:
                name = "%s (extended by %s)" % (cls.__name__, ', '.join(sub.__name__ for sub in subclasses))
                cls = type(name, tuple(reversed(subclasses)), {})
            o = cls()
            members = inspect.getmembers(o, inspect.ismethod)
            for _, mv in members:
                if hasattr(mv, 'routing'):
                    routing = dict(type='http', auth='user', methods=None, routes=None)
                    methods_done = list()
                    
                    for claz in reversed(mv.__self__.__class__.mro()):
                        fn = getattr(claz, mv.__name__, None)
                        if fn and hasattr(fn, 'routing') and fn not in methods_done:
                            methods_done.append(fn)
                            routing.update(fn.routing)
                    if not nodb_only or routing['auth'] == "none":
                        assert routing['routes'], "Method %r has not route defined" % mv
                        endpoint = EndPoint(mv, routing)
                        for url in routing['routes']:
                            if routing.get("combine", False):
                                
                                url = o._cp_path.rstrip('/') + '/' + url.lstrip('/')
                                if url.endswith("/") and len(url) > 1:
                                    url = url[: -1]
                            xtra_keys = 'defaults subdomain build_only strict_slashes redirect_to alias host'.split()
                            kw = {k: routing[k] for k in xtra_keys if k in routing}
                            routing_map.add(werkzeug.routing.Rule(url, endpoint=endpoint, methods=routing['methods'], **kw))
    return routing_map
class AuthenticationError(Exception):