planner/core: refine explain for window function

[alivxxx]

What problem does this PR solve?

Display partition by, order by and frame info for window function in explain.
Fix #8835

What is changed and how it works?

Format partition by, order by and frame info in explain.

Check List

Tests

• Integration test

Code changes

• Has exported function/method change

Side effects

• None

Related changes

• None

[codecov-io]

Codecov Report

Merging #9270 into master will decrease coverage by <.01%.
The diff coverage is 42.3%.

@@            Coverage Diff             @@
##           master    #9270      +/-   ##
==========================================
- Coverage   67.22%   67.22%   -0.01%     
==========================================
  Files         371      371              
  Lines       77303    77353      +50     
==========================================
+ Hits        51968    51997      +29     
- Misses      20692    20714      +22     
+ Partials     4643     4642       -1

Impacted Files	Coverage Δ
planner/core/physical_plans.go	60.86% <ø> (ø)	⬆️
planner/core/stringer.go	93.44% <100%> (ø)	⬆️
planner/core/exhaust_physical_plans.go	94.08% <100%> (ø)	⬆️
planner/core/explain.go	46.66% <40%> (-1.07%)	⬇️
store/tikv/scan.go	73.94% <0%> (-3.37%)	⬇️
executor/join.go	77.86% <0%> (-0.53%)	⬇️
executor/executor.go	67.31% <0%> (+0.27%)	⬆️
executor/distsql.go	73% <0%> (+0.46%)	⬆️
store/tikv/lock_resolver.go	42.65% <0%> (+0.94%)	⬆️
infoschema/infoschema.go	77.63% <0%> (+1.31%)	⬆️
... and 1 more

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[zz-jason]

LGTM

[winoros]

Can we add some unit test for coverage?

[winoros]

lgtm

[alivxxx]

/run-all-tests