Update Newtonsoft.Json version and other nuget versions (use CPM)

[Bertk]

• Update version of Newtonsoft.Json (Package 'Newtonsoft.Json' 9.0.1 has a known moderate severity (coverlet.core) #1505)
• Update documentation (TFM and nuget package versions )
• Remove unnecessary UseDotNet tasks from pipeline
• Remove unnecessary using statements
• Use Central Package Management (CPM)
• resolves Update Mono.Cecil dependency version to 0.11.4 #1351 Package 'Newtonsoft.Json' 9.0.1 has a known moderate severity (coverlet.core) #1505 Newtonsoft.Json vulnerability to DoS attacks in versions before 13.0.1 #1361 datacollector.exe Unable to instrument module: Could not load file or assembly 'System.Reflection.Metadata, Version=1.4.2.0' #1332

alternative: #1513

[Bertk]

@MarcoRossignoli @daveMueller Please review PR.

[daveMueller]

@Bertk Thanks a lot for your time-consuming contributions 🙏 . I've seen your comment in #1511 (comment) regarding this topic but PR was already merged at that time. I think you are right that we don't need them anymore. Especially if we migrate all the test projects to net6.0 like you have done in this PR.
Personally I'm not sure if we shouldn't keep 1-2 legacy netcoreapp3.1 projects to have a wider range of test scenarios regarding instrumentation... What do you think @MarcoRossignoli?
Thanks again, I really like the changes in this PR and will try to do a proper review in the next days.

[MarcoRossignoli]

I suggest to test and ship only supported versions announced here https://learn.microsoft.com/en-us/lifecycle/products/microsoft-net-and-net-core

[Bertk]

This is shows supported versions much better 😉
https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core

[MarcoRossignoli]

@daveMueller is this good to go?

[daveMueller]

@daveMueller is this good to go?

Sorry didn't find time yet to look into it. Most likely on the weekend.