fix: should not set startFunc/stopFunc to 0. when the trans is not finished on taosd stop, it will cause the startFunc/stopFunc setting error

fix: add pre-finished stage, trans won't be dropped in follower if it has undo actions while rollback

fix(query): TSDB_CODE_RPC_VGROUP_NOT_CONNECTED same condition check with TSDB_CODE_RPC_NETWORK_UNAVAIL