expression: Add cast as json push down support for tiflash

[SeaRise]

What problem does this PR solve?

Issue Number: close #48551

Problem Summary:

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[tiprow]

Hi @SeaRise. Thanks for your PR.

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[SeaRise]

/hold
wait for pingcap/tiflash#8333

[codecov]

Codecov Report

Merging #48550 (3b3e662) into master (ccbd1b5) will decrease coverage by 17.5159%.
The diff coverage is 100.0000%.

Additional details and impacted files

@@                Coverage Diff                @@
##             master     #48550         +/-   ##
=================================================
- Coverage   70.9774%   53.4615%   -17.5159%     
=================================================
  Files          1368       1585        +217     
  Lines        405013     596924     +191911     
=================================================
+ Hits         287468     319125      +31657     
- Misses        97528     255317     +157789     
- Partials      20017      22482       +2465     

Flag	Coverage Δ
integration	35.0025% <0.0000%> (?)
unit	70.9679% <100.0000%> (-0.0095%)	⬇️

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

Components	Coverage Δ
dumpling	53.9663% <ø> (ø)
parser	∅ <ø> (∅)
br	55.3003% <ø> (+2.2464%)	⬆️

[SeaRise]

/hold cancel

[SeaRise]

/cc @windtalker @XuHuaiyu

[windtalker]

Others LGTM

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: windtalker, XuHuaiyu

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Needs approval from an approver in each of these files:

• pkg/expression/OWNERS [XuHuaiyu,windtalker]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-11-27 09:02:28.780377394 +0000 UTC m=+826977.445603574: ☑️ agreed by XuHuaiyu.
• 2023-11-28 00:19:37.808178867 +0000 UTC m=+882006.473405061: ☑️ agreed by windtalker.