[Enhancement] Cherry-pick Flat-Json multi-layer into branch-3.3

[Seaven]

Why I'm doing:

What I'm doing:

Cherry-pick list:
[Enhancement] to_json return null when unsupported (#45607)
[Enhancement][FlatJson] optmize dynamic flatten json performance in read process (#49656)
[Enhancement][FlatJson] opitmize flat json compaction performance (#49411)
[Enhancement][FlatJson] support flat json on share-data table (#49616)
[BugFix][FlatJson] Fix json write error when schema change (#49610)
[Enhancement][FlatJson] support multi-layer flat json (#48104)

Fixes #issue

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.3
  • 3.2
  • 3.1
  • 3.0
  • 2.5

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud