feat: remove #[typetag::serde] on PhysicalPlan, Static dispatch implementation of serde using enum.

[KKould]

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Summary

When using #[typetag::serde] for polymorphic serialization, dynamic dispatching via erased_serde results in a deep call stack. This pr uses an enum to convert dynamic dispatching to static dispatching, reducing the call stack depth during serde serialization.

PhysicalPlan after switching to enum serialization, it still supports deserialization of previous versions.

Call stack depth comparison

test from: typetag_serialize_stack_depth_is_measured

main:
typetag serialize stack depth: 41, delta from baseline: 14

pr:
typetag serialize stack depth: 36, delta from baseline: 9

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 

[Copilot]

Pull request overview

This PR replaces the #[typetag::serde] trait object-based polymorphic serialization with an enum-based static dispatch approach to improve performance by reducing call stack depth during serialization.

Key Changes:

• Introduced PhysicalPlanImpl enum containing all 57 physical plan variants
• Implemented backward compatibility for deserializing legacy typetag-formatted data
• Removed #[typetag::serde] attributes from all physical plan implementations

Reviewed changes

Copilot reviewed 49 out of 49 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/query/service/src/physical_plans/physical_plan.rs	Core refactoring: added PhysicalPlanImpl enum, dispatch macros, backward compatibility layer, and tests
src/query/service/src/servers/flight/v1/packets/packet_fragment.rs	Made SerializedPhysicalPlanRef public for inclusion in PhysicalPlanImpl enum
src/query/service/src/servers/flight/v1/packets/mod.rs	Made packet_fragment module public to expose SerializedPhysicalPlanRef
src/query/service/src/physical_plans/physical_limit.rs	Removed #[typetag::serde], made meta field pub(crate)
src/query/service/src/physical_plans/physical_*.rs (40+ files)	Removed #[typetag::serde] from IPhysicalPlan implementations

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[KKould]

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[KKould]

@codex review

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Codex Review: Didn't find any major issues. 🎉

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