This diff hard codes the unsupported message types for creating sidebars from. The `if` check is pretty much identical to the conditions in `thread-creator` right now, just to have a quick working
solution. The next diff will work on extracitng both this and the original check into one single source of truth for what message types should be prevented from having sidebars created from them.
Part of [[ https://linear.app/comm/issue/ENG-4849/thread-from-robotext-about-pinned-message-causing-errors#comment-96a285ec | ENG-4849 ]]