docman_items_type PATCH route should be deprecated

existing route behaviour is now spli int two:
- POST docman_item_type/id/version
this route will be used to create a new version of a document

- PUT docman_items_type/id/metadata
this route will be used to update the metadata of document
at the end of epic it should accept following representation:
{
"title": "..."
"description": "...",
"status",
"obsoclesence _date"
"owner"
"custom_metadata: [
{ ... }
]