Separate and merge .h/.hpp files in duckdb

[myrrc]

• Merge small .h files into vortex_duckdb.h
• Separate C++ code not used in bindgen to .hpp files
• Remove dead code from duckdb: duckdb_vector_to_string, Config,
  ClientContext, duckdb_vx_add_extension_option, DDBString creation.
• Remove rest duckdbfs code. Duckdbfs was partially removed in Remove duckdbfs #8468 but the Rust-side code survived.

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 4 improved benchmarks
❌ 2 regressed benchmarks
✅ 1583 untouched benchmarks
⏩ 4 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	chunked_varbinview_into_canonical[(1000, 10)]	168.8 µs	205.6 µs	-17.86%
❌	Simulation	slice_empty_vortex	310 ns	368.3 ns	-15.84%
⚡	Simulation	bitwise_not_vortex_buffer_mut[128]	273.6 ns	215.3 ns	+27.1%
⚡	Simulation	chunked_varbinview_opt_canonical_into[(1000, 10)]	205.9 µs	169.4 µs	+21.54%
⚡	Simulation	bitwise_not_vortex_buffer_mut[1024]	333.9 ns	275.6 ns	+21.17%
⚡	Simulation	bitwise_not_vortex_buffer_mut[2048]	427.8 ns	369.4 ns	+15.79%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing myrrc/duckdb-less-code (fb66c73) with develop (0726fb9)}

Footnotes

1. 4 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩