Mirror Source Folder Hierarchy In JavaTCSharpCli Output Directory

[lordmilko]

In JavaToCSharpCli, when processing a folder with subdirectories, all discovered files are output to the same output directory. I think it would be useful to able to retain the original folder structure, however I can also see scenarios where somebody might want to flatten everything, so I'm not sure to what extent the default should be changed and/or an option to configure this behavior should be added. I added support for mirroring the source folder structure in my local repo as follows

-private static void ConvertToCSharpDir(DirectoryInfo inputDirectory, DirectoryInfo outputDirectory, JavaConversionOptions options)
+private static void ConvertToCSharpDir(DirectoryInfo inputDirectory, DirectoryInfo rootOutputDirectory, JavaConversionOptions options)
{
    if (inputDirectory.Exists)
    {
        var searchOption = options.IncludeSubdirectories ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly;
        foreach (var f in inputDirectory.GetFiles("*.java", searchOption))
        {
            string? directoryName = f.DirectoryName;
            if (string.IsNullOrWhiteSpace(directoryName))
            {
                continue;
            }

+            var relativePath = Path.GetDirectoryName(f.FullName.Replace(inputDirectory.FullName, string.Empty)?.TrimStart(Path.DirectorySeparatorChar));
+
+            var outputDirectory = string.IsNullOrEmpty(relativePath) ? rootOutputDirectory : new DirectoryInfo(Path.Combine(rootOutputDirectory.FullName, relativePath));
+
            if (!outputDirectory.Exists)
            {
                outputDirectory.Create();
            }

            ConvertToCSharpFile(f,
                new FileInfo(Path.Combine(outputDirectory.FullName, Path.ChangeExtension(f.Name, ".cs"))),
                options,
                false);
        }
    }
    else
    {
        _logger.LogError("Java input folder {path} doesn't exist!", inputDirectory);
    }
}