[From Single File] support from_single_file method for WanAnimateTransformer3DModel

[samadwar]

What does this PR do?

Added support to load checkpoints from a single file where some modifications were required to convert_wan_transformer_to_diffusers method for it to work with WanAnimateTransformer3DModel

best regards,
Sam

Fixes # (issue)

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[DN6]

Hi @samadwar do you have a single file version of Wan Animate we can use to test this PR?

[samadwar]

Hi @samadwar do you have a single file version of Wan Animate we can use to test this PR?

yes, https://huggingface.co/QuantStack/Wan2.2-Animate-14B-GGUF/blob/main/Wan2.2-Animate-14B-Q4_K_M.gguf
or any GGUF file in https://huggingface.co/QuantStack/Wan2.2-Animate-14B-GGUF

or any file from here https://huggingface.co/Kijai/WanVideo_comfy_fp8_scaled/tree/main/Wan22Animate