Now that isInvalidSidebarSource is currently the single source of truth for the valid/invalid message types that can be sidebar sources, it makes sense to update the types for
SidebarSourceMessageInfo SidebarSourceMessageData and RawSidebarSourceMessageInfo to reflect this.
Resolves https://linear.app/comm/issue/ENG-5207/update-types-for-sidebar-source-messages-to-reflect
Depends on D9322