Add return type to conduit.query

Summary: Fixes T6950. Adds the return type of Conduit API methods to the `conduit.query` call.

Test Plan: Called `echo '{}' | arc call-conduit conduit.query` and verified that the return types were present in the response.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T6950

Differential Revision: https://secure.phabricator.com/D11466

src/applications/conduit/method/ConduitQueryConduitAPIMethod.php

@@ -32,6 +32,7 @@ final class ConduitQueryConduitAPIMethod extends ConduitAPIMethod {
     foreach ($classes as $class) {
       $names_to_params[$class->getAPIMethodName()] = array(
         'params' => $class->defineParamTypes(),
+        'return' => $class->defineReturnType(),
       );
     }