enh(query): add new api in taos.h

fix(stream): set child id

fix(stream): set child id

enh(query): enable elapsed function distributed splitting

refactor: index module

feat: split vgroup

feat(wal): support restore from snapshot

feat: drop dnode

fix(os): start win32 taosd case

fix(query): add to_iso8601 function timezone validation

feat(stream): sink table can be other db

feat(stream): stream state window support top and bottom