Add ValueError in GenerateSuccinctContour (#5719)

Signed-off-by: KumoLiu <yunl@nvidia.com>

Fixes #5714.

### Description
Add ValueError when an invalid contour is generated.

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

Signed-off-by: KumoLiu <yunl@nvidia.com>

Author: KumoLiu

monai/apps/pathology/transforms/post/array.py

@@ -458,6 +458,10 @@ def __call__(self, contours: List[np.ndarray]) -> np.ndarray:
                     elif coord[1] == self.width - 1:
                         corner = 2
                         pixel = (int(coord[0] - 0.5), int(coord[1]))
+                    else:
+                        raise ValueError(
+                            f"Invalid coutour coord {coord} is generated, areas may contain boundaries or small holes"
+                        )
                     sequence.append(pixel)
                     last_added = pixel
                 elif i == len(group) - 1: