cuml-cpu notebook, docs and cluster models (#5597)

PR does two things: 

- Adds cuml-cpu notebook
- Adds cluster models to cuml-cpu package

Authors:
  - Dante Gama Dessavre (https://github.com/dantegd)

Approvers:
  - William Hicks (https://github.com/wphicks)
  - Corey J. Nolet (https://github.com/cjnolet)

URL: #5597

docs/source/estimator_intro.ipynb

@@ -295,7 +295,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
   },
@@ -309,7 +309,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.7.8"
+   "version": "3.9.13"
   }
  },
  "nbformat": 4,

python/CMakeLists.txt

@@ -133,6 +133,8 @@ if(CUML_CPU)
   list(APPEND CUML_ALGORITHMS "umap")
   list(APPEND CUML_ALGORITHMS "knn")
   list(APPEND CUML_ALGORITHMS "hdbscan")
+  list(APPEND CUML_ALGORITHMS "dbscan")
+  list(APPEND CUML_ALGORITHMS "kmeans")
 
   # this won't be needed when we add CPU libcuml++ (FIL)
   set(cuml_sg_libraries "")

python/cuml/cluster/__init__.py

@@ -16,13 +16,13 @@
 
 from cuml.internals.device_support import GPU_ENABLED
 
+from cuml.cluster.dbscan import DBSCAN
+from cuml.cluster.kmeans import KMeans
 from cuml.cluster.hdbscan import HDBSCAN
 
 # TODO: These need to be deprecated and moved to hdbscan namespace
 from cuml.cluster.hdbscan.prediction import all_points_membership_vectors
 from cuml.cluster.hdbscan.prediction import approximate_predict
 
 if GPU_ENABLED:
-    from cuml.cluster.dbscan import DBSCAN
-    from cuml.cluster.kmeans import KMeans
     from cuml.cluster.agglomerative import AgglomerativeClustering