exceptions: Add IncompatibleParametersError as a JsonableError.

Creates an IncompatibleParametersError to be used in cases where
there are two (or more) optional parameters for an endpoint that
are incompatible with each other, e.g. there's a parameter for a
user name and a user ID but only one should be sent in the request
to identify the user.

Documents the error on the /api/rest-error-handling article.

Updates the PATCH users/me/subscriptions/muted_topics endpoint to
use this error when both the stream and stream_id parameters are
passed (note this endpoint is currently deprecated).

zerver/lib/streams.py

@@ -7,6 +7,7 @@ from django.utils.translation import gettext as _
 
 from zerver.lib.default_streams import get_default_stream_ids_for_realm
 from zerver.lib.exceptions import (
+    IncompatibleParametersError,
     JsonableError,
     OrganizationAdministratorRequiredError,
     OrganizationOwnerRequiredError,
@@ -326,7 +327,7 @@ def check_for_exactly_one_stream_arg(stream_id: Optional[int], stream: Optional[
         raise JsonableError(error)
 
     if stream_id is not None and stream is not None:
-        raise JsonableError(_("Please supply only one channel parameter: name or ID."))
+        raise IncompatibleParametersError(["stream_id", "stream"])
 
 
 def check_stream_access_for_delete_or_update(