Function xmtp_client_sync_all 

pub unsafe extern "C" fn xmtp_client_sync_all(
    client: *const XmtpFfiClient,
    consent_states: *const i32,
    consent_states_count: i32,
    out_synced: *mut i32,
    out_eligible: *mut i32,
) -> i32

Sync all conversations, optionally filtering by consent states. consent_states is a parallel array of consent state values (0=Unknown, 1=Allowed, 2=Denied). Pass null and 0 to sync all.