Automate the environment setup process

[nwithan8]

Description

Let's make it as easy as possible for someone with a "fresh" Windows machine to get their environment up and running for developing and testing our code.

• New script/Makefile step "setup" installs all required .NET versions and third-party tools (NuGet CLI tool for a variety of functions, SnInstallPfx for signing DLLs)

(Bit of a catch-22 here, as the user WILL still need to install Make (and, perhaps in the process, Chocolatey) to be able to use our Makefile. They could always bypass the Makefile shortcut and simply call the setup.bat script directly via a terminal. The setup.bat script does NOT install Chocolatey or Make.

Testing

• Script run in a fresh Windows installation, works as expected
• No valid concerns from BatCodeCheck

Pull Request Type

Please select the option(s) that are relevant to this PR.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement (fixing a typo, updating readme, renaming a variable name, etc)