fix: invalid msg while alter db replica

fix(query): fix coverity issues.

fix(sync): fix timer bug

test: restore case

refactor(sync): refactor sync

Feature/addIdxToSysTable

fix: fix coverity scan defeats

fix: rm redundance

fix: return 0 usage when pTsdb is null

fix: null column value when build rsma result

enh: add warn log for abnormal monitor value

fix: give clear msg when failed to connect