Restructure pathology transforms (Project-MONAI#2671)

* Restructure transforms into a directory

Signed-off-by: Behrooz <[email protected]>

* Fix a typo

Signed-off-by: Behrooz <[email protected]>

Co-authored-by: Behrooz <[email protected]>

Author: bhashemian

monai/apps/pathology/handlers/__init__.py

@@ -0,0 +1,12 @@
+# Copyright 2020 - 2021 MONAI Consortium
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .prob_map_producer import ProbMapProducer