Fix vortex-jni local path handling, centralise logic in vortex-file

[robert3005]

Existing logic was duplicated between jni and duckdb with slight
differences. JNI logic didn't always handle local paths.

[codspeed-hq]

Merging this PR will not alter performance

⚡ 1 improved benchmark
❌ 2 regressed benchmarks
✅ 1604 untouched benchmarks
⏩ 42 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	bitwise_not_vortex_buffer_mut[128]	244.4 ns	273.6 ns	-10.66%
❌	Simulation	chunked_varbinview_opt_canonical_into[(100, 100)]	305.7 µs	340.9 µs	-10.33%
⚡	Simulation	chunked_varbinview_canonical_into[(1000, 10)]	191.1 µs	154.8 µs	+23.44%

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 claude/vortex-spark-bare-paths-bja1ek (79e94b4) with develop (570f7ed)²}

Footnotes

1. 42 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. ↩

2. No successful run was found on develop (4959939) during the generation of this report, so 570f7ed was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩