Better AutoML parameters for KNN Classifier

Source PR/Issue: #1650 / #1640 .

`blocked-by`: #1695

KNN nearest neighbors parameters set to search n_neighbors 2-12 for initial classifier development. Will await completion of performance testing of KNN classifier to set this.

```
class KNeighborsClassifier(Estimator):
"""
K-Nearest Neighbors Classifier.
"""
name = "KNN Classifier"
hyperparameter_ranges = {
"n_neighbors": Integer(2, 12),
"weights": ["uniform", "distance"],
```