Add none pbr specular alpha blend shader to starter assets

https://forum.substance3d.com/index.php?topic=23637.0

Yes, We have the none pbr specular shader as starter assets which works with alpha test,
But we also need a none pbr specular alpha blend as a starter assets.
I think most game artists would need this when using painter as work。

I notice 2022 alpha dithering has some denoise when displaying, which looks like alpha blend.

But it wont draw the interior part of model when using it .(ex: glass with ice cube)  which is kind annoying。

Please add this as one of the starter shader.