More stats

[cchanms]

Hi openfresh,
I noticed that some useful stats are missing from

gosrt/srtapi/srtapi_cgo.go

Line 395 in 81c6a57

func GetStats(fd int, clear bool) map[string]interface{} {

Do you have plan to add more stats?
https://github.com/Haivision/srt/blob/master/docs/statistics.md

I feel that pktSentACK, pktRecvACK, pktSentNAK, pktRecvNAK are useful for measuring the performance of SRT.

sample PR:
cchanms/gosrt@6cd5c9a

Thanks.

[cchanms]

Hi @thmatuza , would you mind taking a look? Thanks!