Hide Move to Cold Storage actions on Document versions

Steps to reproduce:

1. In Web UI with Nuxeo Cold Storage addon installed, create a new Document with attached blob (e.g. Picture).
2. Version the document (for example: create major version 1.0, make changes/replace blob, create major version 2.0)
3. Make a query to view Document versions, for example in NXQL search:

   SELECT * FROM Document WHERE ecm:isVersion = 1
   

1. Attempt to

• select one of the versions among the results and send to Cold Storage via nuxeo-move-contents-to-cold-storage button in RESULTS_SELECTION_ACTION slot, or
• navigate to Document version and send to Cold Storage via nuxeo-move-content-to-cold-storage in DOCUMENT_ACTION slot

Expected result: actions to send files to Cold Storage should not appear for Document versions.

Actual result: clicking either button results in an error toast being displayed to the user and the following error logged in console:

****** chain ******
Name: Document.MoveToColdStorage
Exception: PropertyException
Caught error: Failed to invoke operation Document.MoveToColdStorage, Cannot set property on a version: content
Caused by: org.nuxeo.ecm.core.api.PropertyException: Failed to invoke operation Document.MoveToColdStorage, Cannot set property on a version: content
****** Hierarchy calls ******
        org.nuxeo.coldstorage.operations.MoveToColdStorage