core: disallow multiple write stmts in single connection and poison tx if half-done write stmt is abandoned

[jussisaurio]

todo description

[codspeed-hq]

Merging this PR will improve performance by 15.71%

⚡ 1 improved benchmark
✅ 637 untouched benchmarks
⏩ 105 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	concat_blobs	1.7 µs	1.5 µs	+15.71%

Tip

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_{Comparing disallow-multi-write-stmts-poison-tx-on-abandon (417fe47) with main (dd4b4d9)}

Footnotes

1. 105 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. ↩