Enhancement: Default constructor

[MikhailGorobets]

It would be useful to generate a default constructor for a struct from C++ code,
For example

Input:

struct StencilOpDesc
{
    STENCIL_OP          StencilFailOp = STENCIL_OP_KEEP;
    STENCIL_OP          StencilDepthFailOp = STENCIL_OP_KEEP;
    STENCIL_OP          StencilPassOp = STENCIL_OP_KEEP;
    COMPARISON_FUNCTION StencilFunc = COMPARISON_FUNC_ALWAYS;
};

Generated:

[StructLayout(LayoutKind.Sequential, Pack = 0)]
public partial struct StencilOpDesc
{
    public Diligent.Core.StencilOp StencilFailOp;
    public Diligent.Core.StencilOp StencilDepthFailOp;
    public Diligent.Core.StencilOp StencilPassOp;
    public Diligent.Core.ComparisonFunction StencilFunc;

    public StencilOpDesc()
    {
        StencilFailOp = StencilOp.Keep;
        StencilDepthFailOp = StencilOp.Keep;
        StencilPassOp = StencilOp.Keep;
        StencilFunc = ComparisonFunction.Always;
     }
}