Rename packages and some assemblies for version 4.0

[CharliePoole]

Given that 4.0 will be breaking, I think it makes sense to start adding "4" to many of the package names:

Packages

NuGet

Two options here. I prefer "NUnit4" provided we can get exclusive use of that prefix from nuget.org.

• NUnit4.ConsoleRunner OR NUnit.ConsoleRunner4
• NUnit4.ConsoleRunner.NetCore OR NUnit.ConsoleRunner4.NetCore
• NUnit4.Console OR NUnit.Console4
• NUnit4.Engine OR NUnit.Engine4
• NUnit4.Engine.Api OR NUnit.Engine4.Api

Chocolatey

• nunit4-console-runner

MSI

• NUnit4.Console

Zip

• NUnit4.Console.Zip

Assemblies

• nunit4-console.exe
• nunit4.engine.dll
• nunit4.engine.core.dll
• nunit4.engine.api.dll
• nunit4-agent.exe
• nunit4-agent-x86.exe

@nunit/engine-team This is a big deal for users, so I'd appreciate your comments, particularly if you see any problems!