Support OLSS Scheduler

OLSS is the most advanced sampler. Can you consider adding it to the scheduler library of diffusers
(https://github.com/alibaba/EasyNLP/tree/master/diffusion/olss_scheduler)

Start by reading the OLSS implementation in the linked EasyNLP diffusion/olss_scheduler directory and the scheduler library in diffusers. Determine the algorithm's integration requirements and expected behavior before proposing the scope. Done means OLSS is available as a diffusers scheduler and its behavior is validated against the reference implementation.

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