Convert the API to use viewsets.
The search function is now a service of the search model
resource.
The simple and advance search are now the same service. The
difference is determined by the URL query. A ?q= means a
simple search. For advanced search pass the search model
fields in the URL query, example: ?q=document_type__label=
Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>