Convert float annotations if possible. (#1987)

* Convert float annotations if possible.

The client converts all arrays to floats.
If a category contains integer labels, and that category is copied, it will contains floats (e.g 1.0 instead of 1).
When that category is put back to the server, it fails in the tiledb code, which does not accept floats.
The solution is to convert a float category to integer, if possible.

  #1984

* updates

server/test/unit/common/test_writable_annotation.py

@@ -284,3 +284,32 @@ class WritableAnnotationTest(unittest.TestCase):
             all_col_schema["cat_B"],
             {"name": "cat_B", "type": "categorical", "categories": ["label_B"], "writable": True},
         )
+
+    def test_put_float_data(self):
+        # verify that OBS PUTs (annotation_put_fbs) are accessible via
+        # GET (annotation_to_fbs_matrix)
+
+        n_rows = self.data.get_shape()[0]
+
+        # verifies that floating point with decimals fail.
+        fbs = make_fbs({"cat_F_FAIL": pd.Series([1.1] * n_rows, dtype=np.dtype("float"))})
+        with self.assertRaises(ValueError) as exception_context:
+            res = self.annotation_put_fbs(fbs)
+        self.assertEqual(str(exception_context.exception), "Columns may not have floating point types")
+
+        # verifies that floating point that can be converted to int passes
+        fbs = make_fbs({"cat_F_PASS": pd.Series([1.0] * n_rows, dtype="float")})
+        res = self.annotation_put_fbs(fbs)
+        self.assertEqual(res, json.dumps({"status": "OK"}))
+
+        # check read_labels
+        labels = self.annotations.read_labels(None)
+        fbsAll = self.data.annotation_to_fbs_matrix("obs", None, labels)
+        schema = schema_get_helper(self.data)
+        annotations = decode_fbs.decode_matrix_FBS(fbsAll)
+        self.assertEqual(annotations["n_rows"], n_rows)
+        all_col_schema = {c["name"]: c for c in schema["annotations"]["obs"]["columns"]}
+        self.assertEqual(
+            all_col_schema["cat_F_PASS"],
+            {"name": "cat_F_PASS", "type": "int32", "writable": True},
+        )