Add SAM export variants w/ input boxes

[xenova]

What does this PR do?

This PR adds 2 new variants for SAM: one with input_boxes (and no input_points) and one with both input_points and input_boxes.

Fixes # (issue)

Before submitting

• [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• [ ] Did you make sure to update the documentation with your changes?
• [ ] Did you write any new necessary tests?

[HuggingFaceDocBuilderDev]

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[hylarucoder]

really need this!!