[Datalake][Blob]Fix class type and doc (Azure#20805)

Azure#20772

Author: xiafu-msft

sdk/storage/azure-storage-blob/azure/storage/blob/_models.py

@@ -319,6 +319,8 @@ class ContainerProperties(DictMixin):
     dictionary interface, for example: ``container_props["last_modified"]``.
     Additionally, the container name is available as ``container_props["name"]``.
 
+    :ivar str name:
+        Name of the container.
     :ivar ~datetime.datetime last_modified:
         A datetime object representing the last time the container was modified.
     :ivar str etag:

sdk/storage/azure-storage-file-datalake/azure/storage/filedatalake/_models.py

@@ -23,9 +23,11 @@
 from ._shared.models import DictMixin
 
 
-class FileSystemProperties(object):
+class FileSystemProperties(DictMixin):
     """File System properties class.
 
+    :ivar str name:
+        Name of the filesystem.
     :ivar ~datetime.datetime last_modified:
         A datetime object representing the last time the file system was modified.
     :ivar str etag: