Dataset-saving infrastructure phase 1

[SolarDrew]

Closes #671

[codspeed-hq]

Merging this PR will not alter performance

✅ 14 untouched benchmarks
🆕 2 new benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
🆕	Simulation	test_dataset_save[inversion]	N/A	3 s	N/A
🆕	Simulation	test_dataset_save[large_visp_dataset]	N/A	665.5 ms	N/A

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_{Comparing SolarDrew:filesaving (cf95e9b) with main (b280f21)¹}

Footnotes

1. No successful run was found on main (126f423) during the generation of this report, so b280f21 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[SolarDrew]

I'm sure there are other issues remaining but the bulk of the current error are due to slicing bugs in Inversion, which should be solved by #690

[SolarDrew]

I've merged #690 and #695 for now so that the tests are actually testing the changes in this PR. Once those are merged I'll rebase and tidy up the history.

[SolarDrew]

pre-commit.ci autofix

[Cadair]

(Blocking because of git dependency)

[Cadair]

Think it still needs the 2nd changelog entry but not that important.