Add Euler Dy and Eyler Smea Dy samplers

[Endebert]

Taken from https://github.com/Koishi-Star/Euler-Smea-Dyn-Sampler.

Adding them was trivial, so here's the corresponding PR.

[pamparamm]

I think it's a little bit early to add these samplers to the upstream. There are some possible issues with the original implementation (see https://github.com/Koishi-Star/Euler-Smea-Dyn-Sampler/issues/5#issue-2232652349 and https://github.com/Koishi-Star/Euler-Smea-Dyn-Sampler/issues/7#issue-2232823982). Plus, as implied by NovelAI, SMEA should be applicable to all k_diffusion samplers, not just Euler.

[silvertuanzi]

I think it's a little bit early to add these samplers to the upstream. There are some possible issues with the original implementation (see Koishi-Star/Euler-Smea-Dyn-Sampler#5 (comment) and Koishi-Star/Euler-Smea-Dyn-Sampler#7 (comment)). Plus, as implied by NovelAI, SMEA should be applicable to all k_diffusion samplers, not just Euler.

You're right. This is not the original SMEA(since NovelAI had never publish how to), but only a trial, which just want to reproduce similar effect like SMEA Dyn. Now it has some improvement in generating good hands and eyes, but still need further adjustment, so maybe it's not a good idea to merge into ComfyUI so fast.