[feature request] support webp image format

[beenotung]

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System information

• TensorFlow.js version (you are using): 4.20.0
• Are you willing to contribute it (Yes/No): Yes

Describe the feature and the current behavior/state.

Currently, tf.node.image.decodeImage() supports jpeg, png, gif, and bmp. webp is not supported.

Will this change the current api? How?

Yes, tf.node.image.decodeImage() will be updated to support webp;

tf.node.image.decodeWebp() and tf.node.image.encodeWebp() can be added as well.

Who will benefit with this feature?

Users having existing dataset as webp images can load it directly without extra pre-processing, and those who want to save disk space can convert existing images into webp.

Any Other info.