Function indy_sys::did::indy_get_endpoint_for_did

#[no_mangle]
pub unsafe extern "C" fn indy_get_endpoint_for_did(
    command_handle: CommandHandle, 
    wallet_handle: WalletHandle, 
    pool_handle: PoolHandle, 
    did: CString, 
    cb: Option<ResponseStringStringCB>
) -> Error