[trel-dnssd] parse `xa` TXT value as binary (#1234)
[trel-dnssd] parse `xa` TXT value as binary (#1234)


openthread/ot-br-posix,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter