Should we drop netstandard20 support from v10

[iancooper]

There are a lot of niggles around our continued support for netstandard20. To name the most painful of them:

• Poorer support for language features such as nullable or missing support for other features or libs (Timers etc.)
• Lack of EF support for netstandard20 (we multi-target, but to deprecated packages)

Now we could work around this. We could use polyfils to fix the missing language features, and we could just drop support gradually, as an assemblies dependencies drop netstandard20, we follow along. That might allow us to keep the core on netstandard20 longer.

But the real question here is: is it worth it?

• Should we just drop netstandard20 support in V10.

Do we exist in scenarios where the folks who use us need netstandard, and if they do, could persist on v9