compression zstd alogrithem support

[bung87]

https://github.com/bung87/amysql/tree/zstd
run sudo tcpdump -i pktap,lo0 port 3306 -n -q -tttt -s 0 -A on mac shows:
=h..=h..........test
but select * from mysql.general_log shows mysql server didn't get that packet when sending init db command with test.

also it's not clear to me what's the protocol-compression-algorithms value set on server side that support uncompress and zstd
https://dev.mysql.com/worklog/task/?id=12475#New_system_variables:

initial complete in devel branch, some code may need better performance care.

[bung87]

when compression enable and authenticate ,packet will use 7 length header and follow a 4 length header