fix: crash if reader is already dropped

fix(vnode/mgmt): pre close vnode after queue's empty

ci:add ci for keepColumnName

enh(query): handle getBufPage return NULL when no available disk spaces

fix: send rpc response on closing sync or failing to enqueue

fix: 'show user privilegs' command echo user name incomplete

fix: fix ASSERTs

feat: add batch get table vgId API

enh(query): opt filter perf.

enh: use diff atomic op

fix:  varchar type order by rule different with nchar type

fix: drop task while task executing issue