[Feature Request] add more simpler Stable Diffusion model and add decrease for brush and more

[wolfkingal2000]

Add more simpler Stable Diffusion model like :DPM2 a, DPM++ 2S a ,DPM++ 2M, DPM2 a Karras , DPM2 a Karras. DPM++ 2S a Karras, DPM++ 2M Karras add decrease for brush for edit mask and 1 bug when copy image change color, please fix that and for background removing use this very good result :https://github.com/SkyTNT/anime-segmentation/ and thanks for wonderful software