[server] Fix fetchMessageRowsByIDs for CREATE_SUB_THREAD message

Summary: When working on creating sidebars from robotext messages, I discovered for create_sub_thread we did not fetch permissions, and in return we got null

Test Plan: Tested with my local changes to make sure for correct id returned message was correct

Reviewers: ashoat, palys-swm

Reviewed By: ashoat

Subscribers: zrebcu411, Adrian, atul, subnub

Differential Revision: https://phabricator.ashoat.com/D613