The new msg of limit exceed: "Memory exceed limit. %msg, Backend:%ip, fragment:%id Used:% , Limit:%. xxx".
This commit unifies the msg of 'Memory exceed limit' such as check_query_state, RETURN_IF_LIMIT_EXCEEDED and LIMIT_EXCEEDED.
Help to locate big query when system overload, by checking consumptions of running parts of current all queries or specified one query. Its basic mode of work is as follows: firstly trigger BE to report RuntimeProfiles, and wait a moment. secondly caculate consumptions with RuntimeProfiles reported by BE. The consumptions supported by it are the cost of running ExecNode in query when call it.
