expression:add support for JSON_MERGE_PRESERVE

[shinytang6]

What problem does this PR solve?

This PR solves part #7546 (add JSON_MERGE_PRESERVE)

What is changed and how it works?

Migrate the implementation of deprecated JSON_MERGE to JSON_MERGE_PRESERVE.

Check List

• Unit test

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This change is 

[shinytang6]

Can anyone help review that?

[morgo]

PTAL @zz-jason

[codecov-io]

Codecov Report

Merging #8931 into master will increase coverage by 0.01%.
The diff coverage is 81.81%.

@@            Coverage Diff             @@
##           master    #8931      +/-   ##
==========================================
+ Coverage   67.58%   67.59%   +0.01%     
==========================================
  Files         364      364              
  Lines       75441    75451      +10     
==========================================
+ Hits        50988    51004      +16     
+ Misses      19959    19954       -5     
+ Partials     4494     4493       -1

Impacted Files	Coverage Δ
expression/builtin_json.go	76.15% <81.81%> (+0.48%)	⬆️
executor/join.go	77.92% <0%> (-0.52%)	⬇️
executor/distsql.go	73% <0%> (+0.46%)	⬆️
expression/schema.go	94.95% <0%> (+0.84%)	⬆️
store/tikv/lock_resolver.go	42.65% <0%> (+0.94%)	⬆️
util/systimemon/systime_mon.go	100% <0%> (+20%)	⬆️

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[alivxxx]

LGTM

[zz-jason]

LGTM

[zz-jason]

/run-all-tests

[zz-jason]

/run-unit-test