Add export pair of varying parameter and geometry input.

After this fix. We can get bind_vertex_input parameters.

Ex. After
```  <library_visual_scenes>
    <visual_scene id="VisualSceneNode" name="sample_cgfx">
      <node id="pSphere1" name="pSphere1" type="NODE">
        <matrix sid="transform">1 0 0 10 0 1 0 0 0 0 1 30 0 0 0 1</matrix>
        <instance_geometry url="#pSphereShape1">
          <bind_material>
            <technique_common>
              <instance_material symbol="cgfxShader3SG" target="#material_c">
                <bind_vertex_input semantic="POSITION0" input_semantic="POSITION"/>
                <bind_vertex_input semantic="NORMAL0" input_semantic="NORMAL"/>
                <bind_vertex_input semantic="TEXCOORD0" input_semantic="TEXCOORD" input_set="0"/>
                <bind_vertex_input semantic="TANGENT0" input_semantic="TEXTANGENT" input_set="0"/>
                <bind_vertex_input semantic="BINORMAL0" input_semantic="TEXBINORMAL" input_set="0"/>
              </instance_material>
```
Ex. Before
```  <library_visual_scenes>
    <visual_scene id="VisualSceneNode" name="sample_cgfx">
      <node id="pSphere1" name="pSphere1" type="NODE">
        <matrix sid="transform">1 0 0 10 0 1 0 0 0 0 1 30 0 0 0 1</matrix>
        <instance_geometry url="#pSphereShape1">
          <bind_material>
            <technique_common>
              <instance_material symbol="cgfxShader3SG" target="#material_c"/>
```