Specify marshaling for P/Invoke string arguments (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2101)

Specify marshaling for P/Invoke string arguments (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2101)

- Add lib or ref assemblies for the netstandard2.1 target framework

- Add lib or ref assemblies for the netstandard2.0 target framework

- Add lib or ref assemblies for the net8.0 target framework

Some target frameworks declared in the dependencies group of the nuspec and the lib/ref folder do not have exact matches in the other location. Consult the list of actions below:

- Add lib or ref assemblies for the netstandard2.1 target framework

- Add lib or ref assemblies for the netstandard2.0 target framework

- Add lib or ref assemblies for the net8.0 target framework