Refactor the model accesors

Refactor the accesors to behave like methods instead of properties.
This means all accesors will be prepended with the string
"get_" and will include a set of parenthesis.

Improve the ModeAttribute class to use the method's
short_description. This commit also adds support for a
new method .help_text attribute has been added.

Move accessors to their own module, named "methods.py".

Remove the PropertyHelper class as the accessors no longer
need it.

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

mayan/apps/ocr/utils.py

@@ -4,20 +4,24 @@ from django.apps import apps
 from django.utils.encoding import force_text
 
 
-def get_document_ocr_content(document):
+def get_document_content_iterator(document):
+    latest_version = document.latest_version
+
+    if latest_version:
+        return get_document_version_content_iterator(
+            document_version=latest_version
+        )
+
+
+def get_document_version_content_iterator(document_version):
     DocumentPageOCRContent = apps.get_model(
         app_label='ocr', model_name='DocumentPageOCRContent'
     )
 
-    for page in document.pages.all():
+    for page in document_version.pages.all():
         try:
             page_content = page.ocr_content.content
         except DocumentPageOCRContent.DoesNotExist:
             return
         else:
             yield force_text(page_content)
-
-
-@property
-def document_property_ocr_content(self):
-    return ' '.join(get_document_ocr_content(self))