Draft: add Doxygen strings to the packages' __init__ files

The packages are `draftfunctions`, `draftgeoutils`, `draftguitools`,
`draftmake`, `draftobjects`, `drafttaskpanels`, `drafttests`,
`draftutils`, `draftviewproviders`.

src/Mod/Draft/drafttests/__init__.py

@@ -39,3 +39,6 @@ on how to write unit tests.
         def test_new_tool(self):
             pass
 """
+## \defgroup drafttests drafttests
+# \ingroup DRAFT
+# \brief Modules that define classes used for unit testing the workbench.