Update buildsystem to Cake.Recipe 2.0.0

[nils-a]

Steps should include:

• Change pre-processor directive
• Pin to updated version of Cake - 0.38.4
• Remove input parameters which are no longer required, for example shouldRunGitVersion: true as this is now the default
• Update bootstrapper to include --bootstrap command
• Project is using an embedded icon
• Project is using a deterministic build - --target=Enable-DeterministicBuild
• Rename AppVeyor default target - AppVeyor -> CI
• Update GitVersion.yml file with the required changes for using new version of GitVersion
• Add CakeContrib.Guidelines Nuget Package and add PackageIcon to csproj
• Remove usage of nuspec file(s) for NuGet packages, instead, we will run DotNetCore-Pack
• Add shouldUseDeterministicBuilds: true parameter
• Check for usage of shouldRunCodecov: true which is not required anymore - this is new default
• Add Cake.Addin.Analyzer package
• Add settings.json file for VSCode
• Add dependabot config file
• Add GitHub Actions
• Switch to Cake.Tool rather than Cake.exe
• Switch to not running PR's on AppVeyor
• Check for trailing spaces in the TestCoverageFilter
• Ensure targeting netstandard2.0 for project and netcoreapp2.1 and netcoreapp3.1 for tests
• Ensure AppVeyor build image is using latest
• Fix broken unit tests
• Fix dupFinderExcludePattern for multi-targetting platforms
• Update bootstrappers to use .Net Global Tool
• Update appveyor.yml file to bust cache based on change to .net global tool json file, rather than packages.config file
• Delete packages.config file
• Update .gitignore file to no longer exclude the packages.config file