feat:optimize for group by tag

Feature/3 liaohj

feat: order by distributed split

feat: group by distributed split

fix: add htonl to numOfBlocks

test: case for alter db replica

fix: a problem of parser async

fix(os): win python case error

fix(query): set null for empty min/max

test: add testcase of muti-replica mnode

enh(qurey): enable async APIs in taos.h