Commit d3f4f5f208 introduced automatic conversion to FileInfo and DirectoryInfo but failed to properly handle the conversion if the value comes from the [DefaultValue] attribute.
Using both `var (converter, stringConstructor) = GetConverter(...)` and `var (converter, _) = GetConverter(...)` should have been a red flag!
Add support for converting command parameters that doesn't have a built-in TypeConverter but has a constructor that takes a string. For CLI apps, FileInfo and DirectoryInfo will likely be the most useful ones, but there may be others.
When a conversion to an enum fails, list all the valid enum values in the error message.
Message before this commit:
> Error: heimday is not a valid value for DayOfWeek.
Message after this commit:
> Error: Failed to convert 'heimday' to DayOfWeek. Valid values are 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'
