1. Support prefetch some column stats when FE booted, it would load column stats that was got updated recently according to the comment of PR #18460 from @morrySnow
2. Refactor stats cache, split histogram cache from column stats, so that we could avoid some redundant query for column statistics table,for example, update the histogram or column stats only, in the previous implementation a united cache loader would send query request to both column stats table and histogram table,
3. Extract some common logic to StatsUtil
4. Remove some useless codes in unit tests, those codes is hard to maintaince and it's not a good idea for testing the accurracy of stats estimation according to the advise from @englefly
5. Add field type restriction when create analysis tasks to avoid unnecessary failure
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