Enhance the default presets to be self contained in Visual Studio #1871
Description
The unoapp template's blank and recommended presets require the use of Directory.Build.*, which make them difficult to include in existing projects.
These files are needed in some of the scenarios, such as when explicit packages are added such as the server project or test projects.
The enhancement should have the template not generate the Directory.Build.* files when no nuget packages are required by the configuration switches, and move the original content from the Directory.Build.* into the csproj. It should also not include the CPM feature, which would make it inherit from the current solution's configuration, if any.