Add missing ModelProperty label entires

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

HISTORY.rst

@@ -8,6 +8,8 @@
   tests.
 - Rename expected_content_type to expected_content_types
   and allow a list of content types to be specified.
+- Add missing label to metadata and file metadata model
+  properties entries.
 
 
 3.2.9 (2019-11-03)

mayan/apps/file_metadata/apps.py

@@ -92,10 +92,11 @@ class FileMetadataApp(MayanAppConfig):
         )
 
         ModelAttribute(
-            model=Document, name='file_metadata_value_of',
+            model=Document,
+            name='file_metadata_value_of.< dotted path to driver and property >',
             description=_(
                 'Return the value of a specific file metadata.'
-            )
+            ), label=_('File metadata value of')
         )
 
         ModelEventType.register(

mayan/apps/metadata/apps.py

@@ -93,10 +93,10 @@ class MetadataApp(MayanAppConfig):
         )
 
         ModelAttribute(
-            model=Document, name='metadata_value_of',
+            model=Document, name='metadata_value_of.< metadata type name >',
             description=_(
                 'Return the value of a specific document metadata'
-            )
+            ), label=_('Metadata value of')
         )
 
         ModelField(