Function extract_thread_root

pub fn extract_thread_root(
    event: &Raw<AnySyncTimelineEvent>,
) -> Option<OwnedEventId>

Try to extract the thread root from a timeline event, if provided.

The thread root is the field located at content.m.relates_to.event_id, if the field at content.m.relates_to.rel_type is m.thread.

Returns None if we couldn’t find a thread root, or if there was an issue during deserialization.