Support net 8, net 9, net 10, net 11 in one dotnet-scaffold version

Add the ability to scaffold net 8, net 9, net 10, net 11 all from the same `dotnet scaffold` package version. This involves allowing for backwards compatibility and target framework detection.

`dotnet scaffold` adds generated code for user projects. Right now, `dotnet scaffold` is separated by releases so there is a different version for each intended framework (example `dotnet scaffold --version 8.0.13` is intended for scaffolding net 8 projects). This update to have one `dotnet scaffold` package support all net versions involves storing each of the generated templates from each of these different release branches in the most recent version of `dotnet scaffold`. Each of these templates will be stored in different folders in order to categorize them. As a new version of net is supported, we will add a new folder with a copy of the the most recent version of the templates and update those. When the templates are used, the respective target framework folder will be searched for the correct template.

Allow for dotnet scaffold contain the generated code for each target framework version, adding target framework detection, and correct template selection.