Add and consume validation helpers, remove unused interface

[jviau]

Adds some validation helpers to simplify argument verification, leveraging the CallerArgumentExpressionAttribute. Also removes IDurableTaskRegistry as that is no longer used - the concrete options type in Worker.Core.csproj is used now.

[cgillum]

Looks like there's a test failure:

[xUnit.net 00:00:01.15]     Microsoft.DurableTask.Worker.Tests.DefaultDurableTaskBuilderTests.BuildTarget_ValidType_Sets [FAIL]
  Failed Microsoft.DurableTask.Worker.Tests.DefaultDurableTaskBuilderTests.BuildTarget_ValidType_Sets [18 ms]
  Error Message:
   System.ArgumentNullException : Value cannot be null. (Parameter 'value')
  Stack Trace:
     at Microsoft.DurableTask.Check.NotNull[T](T argument, String name) in /home/runner/work/durabletask-dotnet/durabletask-dotnet/src/Shared/Validation/Check.cs:line 67
   at Microsoft.DurableTask.Check.ConcreteType[TImplements](Type argument, String name) in /home/runner/work/durabletask-dotnet/durabletask-dotnet/src/Shared/Validation/Check.cs:line 107
   at Microsoft.DurableTask.Worker.DefaultDurableTaskBuilder.set_BuildTarget(Type value) in /home/runner/work/durabletask-dotnet/durabletask-dotnet/src/Worker/Core/DependencyInjection/DefaultDurableTaskBuilder.cs:line [40](https://github.com/microsoft/durabletask-dotnet/actions/runs/3253189718/jobs/5340212656#step:7:41)
   at Microsoft.DurableTask.Worker.Tests.DefaultDurableTaskBuilderTests.BuildTarget_ValidType_Sets() in /home/runner/work/durabletask-dotnet/durabletask-dotnet/test/Worker/Core.Tests/DependencyInjection/DefaultDurableTaskBuilderTests.cs:line 28