Add new diffusion samplers

[manuelgloeckler]

🚀 Feature Request

Is your request related to a problem?

In #1226, we began implementing alternative samplers (e.g., DDIM) during the last hackathon. Since then, several efficient samplers have been proposed in the literature that aim to solve the SDE with fewer steps. It would be beneficial to integrate some of these well-performing and easy-to-maintain approaches into this project.

Describe the solution you'd like

To enhance SBI, the following steps should be taken:

• Choose a sampler from recent literature that you'd like to implement and map its notations/definitions to the quantities used in this library.
• Add the chosen sampler to the Predictor.

📌 Additional Context

Relevant Literature:

• [1] "Elucidating the Design Space of Diffusion-Based Generative Models" – Arxiv link
• [2] "SEEDS: Exponential SDE Solvers for Fast High-Quality Sampling from Diffusion Models" – Arxiv link
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