[segment-anything] Support multi-point as the prompt input (#945)

* [sam] Support multi-point prompts

* [segment-anything] Pass points by reference

* [segment-anything] Update example code and image

* Fix clippy lint.

---------

Co-authored-by: Yun Ding <yunding@nvidia.com>
Co-authored-by: laurent <laurent.mazare@gmail.com>

candle-wasm-examples/segment-anything/src/bin/m.rs

@@ -94,7 +94,7 @@ impl Model {
             &embeddings.data,
             embeddings.height as usize,
             embeddings.width as usize,
-            Some((x, y)),
+            &[(x, y)],
             false,
         )?;
         let iou = iou_predictions.flatten(0, 1)?.to_vec1::<f32>()?[0];