Modified structured_data hook interface slightly to check for and cal…

…l the "finish" attribute/callable hook.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "dcicutils"
-version = "8.14.2.1b3"  # TODO: To become 8.14.3
+version = "8.14.2.1b4"  # TODO: To become 8.14.3
 description = "Utility package for interacting with the 4DN Data Portal and other 4DN resources"
 authors = ["4DN-DCIC Team <support@4dnucleome.org>"]
 license = "MIT"