Fix enums/errors case names shadowing parameters to top level type names

[arg0d]

If associated enum class name matches it's parameter type name, prefix the parameter type with package namespace to restrict the compiler from picking the associated enum class instead of top level type definition

Before

public record Rectangle(double @width, double @height) { }
public record Shape
{                    ____________
                     ∨          ∧
    public record Rectangle(Rectangle @s) : Shape { }
    public record Ellipse(Ellipse @s) : Shape { }
}

After

namespace my_namespace;
public record Rectangle(double @width, double @height) { }
public record Shape ^_______________________
{                                           ^
    public record Rectangle(my_namespace.Rectangle @s) : Shape { }
    public record Ellipse(Ellipse @s) : Shape { }
}

Fixes #60

@itrumper