refactor(handler): share inspector execution flow

[NithinPJ998]

Summary

• Add shared handler helpers for top-level execution, system calls, first-frame gas setup, and the frame loop.
• Route InspectorHandler through those helpers while preserving inspector-specific frame hooks.
• Keep the existing Handler and InspectorHandler default entry points intact so downstream implementations do not need to add new required trait methods.

[codspeed-hq]

Merging this PR will improve performance by 3.9%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
✅ 175 untouched benchmarks
⏩ 1 skipped benchmark¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	EXTCODECOPY_50	51.9 µs	49.9 µs	+3.9%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing NithinPJ998:share-inspector-execution-flow (9f3ec27) with main (69b54cc)}

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩