Add Nextorm to benchmarks

[AlexeyShirshov]

Please, take a look at this PR. I add Nextorm lib and make benchmark project to support net8.0. Also fix sql server connection issue for EF core.

[mgravell]

Unless I'm misunderstanding, nextorm is brand new, barely seen - is that right? In that case, I doubt it has enough maturity to be worth adding here yet. It might be better if you fork things and do this locally for now, and then if nextorm gets some momentum, we can see about merging it in. However, I do think we've had some worthwhile discussion here, that might help influence design choices (especially around how you measure performance in terms of reusable objects, which could have significant impact on the design)