chore(explain): Adds support for explain subquery in plans

[forsaken628]

I hereby agree to the terms of the CLA available at: https://docs.databend.com/dev/policies/cla/

Summary

explain raw select * from numbers(1) as t where exists (select number as a from numbers(1) where number = t.number)
----
EvalScalar
├── scalars: [t.number (#0) AS (#0)]
└── Filter
    ├── filters: [SUBQUERY]
    ├── subquerys
    │   └── Subquery (Exists)
    │       ├── output_column: system.numbers.number (#1)
    │       └── EvalScalar
    │           ├── scalars: [numbers.number (#1) AS (#1)]
    │           └── Filter
    │               ├── filters: [eq(numbers.number (#1), t.number (#0))]
    │               └── Scan
    │                   ├── table: system.numbers (#1)
    │                   ├── filters: []
    │                   ├── order by: []
    │                   └── limit: NONE
    └── Scan
        ├── table: system.numbers (#0)
        ├── filters: []
        ├── order by: []
        └── limit: NONE

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):

---

This change is 

[BohuTANG]

The yaml files in the https://github.com/forsaken628/databend/tree/explain_subquery/src/query/service/tests/it/sql/planner/optimizer/data/cases need to modify.