feat: remove multipart support

It is broken since Python 3 and is unused.

It is difficult to maintain support for this with CSRF checks.

cubicweb_rqlcontroller/views.py

@@ -94,17 +94,8 @@ class RqlIOController(Controller):
       {'login': 'babar', 'pw': 'cubicweb rulez & 42'}),
      ('INSERT CWGroup G: G name %(name)s',
       {'name': 'pachyderms'}),
-     ('SET U in_group G WHERE G eid %(g)s, U eid %(u)s',
-      {'u': '__r0', 'g': '__r1'}),
-     ('INSERT File F: F data %(content)s, F data_name %(fname)s',
-      {'content': '__f0', 'fname': 'toto.txt'}),
     ]
 
-    The later query is an example of query built to upload binety
-    data as a file object. It requires to have a multipart query
-    in which there is a part holding a file named '__f0'. See
-    cwclientlib for examples of such queries.
-
     Limitations: back references can only work if one entity has been
     created.
 
@@ -113,27 +104,15 @@ class RqlIOController(Controller):
     __regid__ = "rqlio"
     __select__ = (
         match_http_method("POST")
-        & match_request_content_type(
-            "application/json", "multipart/form-data", mode="any"
-        )
+        & match_request_content_type("application/json")
         & match_form_params("version")
     )
     require_csrf = False
 
     def json(self):
         contenttype = self._cw.get_header("Content-Type", raw=False)
-        if (contenttype.mediaType, contenttype.mediaSubtype) == (
-            "application",
-            "json",
-        ):  # noqa: E501
-            encoding = contenttype.params.get("charset", "utf-8")
-            content = self._cw.content
-        else:
-            # Multipart content is usually built by
-            # cubicweb.multipart.parse_form_data() which encodes using
-            # "utf-8" by default.
-            encoding = "utf-8"
-            content = self._cw.form["json"][1]
+        encoding = contenttype.params.get("charset", "utf-8")
+        content = self._cw.content
         try:
             # here we use .read instead of .gevalue because
             # on some circumstances content is an instance of BufferedRandom

test/unittest_rqlcontroller.py

@@ -95,30 +95,6 @@ class RqlIOTC(PyramidCWTest):
         self.assertEqual(2, len(output[2]))
         self.assertEqual([output[0][0], output[1][0]], output[2])
 
-    def test_queries_multipart(self):
-        queries = [
-            (
-                "INSERT CWUser U: U login %(l)s, U upassword %(p)s",
-                {"l": "Babar", "p": "cubicweb rulez & 42"},
-            ),
-            ('INSERT CWGroup G: G name "pachyderms"', {}),
-            (
-                "SET U in_group G WHERE U eid %(u)s, G eid %(g)s",
-                {"u": "__r0", "g": "__r1"},
-            ),
-        ]
-        self.webapp.login(user="admin", password=self.password)
-        files = [("json", "loutre.json", json.dumps(queries).encode("utf-8"))]
-
-        self.webapp.post(
-            "/rqlio/1.0",
-            upload_files=files,
-            headers={
-                "Accept": "application/json",
-            },
-            do_not_grab_the_crsf_token=True,
-        )
-
     def test_rewrite_args_errors(self):
         rql1 = "Any U WHERE U login %(l)s"
         rql2 = 'SET U in_group G WHERE G name "managers", U eid %(u)s'