[Feature Request] Inpaint mask content settings.

A1111 for example has the option of what content you want to be in the mask when you send it to the sampler when using inpainting:

It is a very important feature when you try to use inpainting model and set the denoising strength less than 1.0. now if you do that you only get a grey background in the masked area. It is caused by the preprocessing of inpainting VAE encode.

Some people would say I can use the set_latent_noise_mask node, but I just want to use inpainting model, and set_latent_noise_mask node is not compatible with it. Inpainting model is much better in the consistence between masked area and unmasked area.