Adding Vae Decoder in Wan

[mohiso22]

No description provided.

[quic-amitraj]

Refer flux pipeline for the changes and removed not needed class.

[quic-amitraj]

To handle two different types of get_onnx_params for image and video pipelines, let's have two different methods like this:
def get_onnx_image_params(self)

def get_onnx_video_params(self)

Later inside init of pipeline map with the desired method with get_onnx_params like this-
self.vae_decode.get_onnx_params= self.vae_decode.get_onnx_image_params

[quic-amitraj]

To handle two different types of get_onnx_params for image and video pipelines, let's have two different methods like this: def get_onnx_image_params(self)

def get_onnx_video_params(self)

Later inside init of pipeline map with the desired method with get_onnx_params like this- self.vae_decode.get_onnx_params= self.vae_decode.get_onnx_image_params

update flux init as well to reflect this changes.

[quic-amitraj]

LGTM