chore(query): explain ast work like explain syntax

[sundy-li]

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Summary

simple ast visitor, make explain ast work like explain syntax

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[BohuTANG]

cc@soyeric128 The format of EXPLAIN AST changed after this PR: https://docs.databend.com/sql/sql-commands/explain-cmds/explain-ast, need updated.