feat(frontend/expr): boolean constant folding for (Is, IsNot) x (True, False, Null)

[Enter-tainer]

What's changed and what's your intention?

• Summarize your change (mandatory)

Add constant folding for IsTrue, IsFalse, IsNull, IsNotTrue, IsNotFalse, IsNotNull. NULL is taken into account as well. For example, NULL IS NOT TRUE will become True.

Checklist

• I have written the necessary docs and comments
• I have added necessary unit tests and integration tests

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #2265 (5084ca5) into main (d75b905) will increase coverage by 0.00%.
The diff coverage is 80.43%.

@@           Coverage Diff           @@
##             main    #2265   +/-   ##
=======================================
  Coverage   71.24%   71.25%           
=======================================
  Files         655      655           
  Lines       83502    83538   +36     
=======================================
+ Hits        59488    59521   +33     
- Misses      24014    24017    +3     

Flag	Coverage Δ
rust	71.25% <80.43%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/frontend/src/expr/utils.rs	97.73% <80.43%> (-0.89%)	⬇️
src/common/src/types/ordered_float.rs	24.30% <0.00%> (+0.19%)	⬆️

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[neverchanje]

lgtm