FIX
1. remove float and double literal toString and getStringValue introduced by
PR #23504 and PR #23271
These functions lead to wrong cast result of double and float literal
2. fix compute signature for datetimev2 always produce scale 6
3. fix stats calculator failed when generate node stats with two same column
4. constant fold on fe failed when cast double to integral
TODO
after fix the first problem, some mv matching not work well, fix them later
- test_dup_mv_div
- test_dup_mv_json
- test_tcu
