Helpers for reading an arbitrary Stream

[airbreather]

Desired usage:

public static void MyMethod(Stream stream, int bufferSize)
{
    var visitor = new MyVisitor();
    CsvReader.Process(stream, bufferSize);
}

public static async Task MyMethod(Stream stream, int bufferSize, IProgress<int> progress = null, CancellationToken cancellationToken = default)
{
    var visitor = new MyVisitor();
    await CsvReader.ProcessAsync(stream, bufferSize, progress, cancellationToken);
}

The IProgress<int> instance would receive the return of each Stream.Read or Stream.ReadAsync call after that chunk has been fully processed.