Modify Sonador authorization to utilize a filter method in the Python plugin

Update: the advanced authorization plugin is being maintained again and the Orthanc team has implemented many of the features needed for user-account mediated access to resource in Orthanc.

The advanced authorization plugin which is currently used to integrate Orthanc and Sonador has been deprecate. (See https://book.orthanc-server.com/plugins/authorization.html for details.) The new recommended way to handle authorization within Orthanc is via a Filter method and the Python plugin. (See https://book.orthanc-server.com/plugins/python.html#python-authorization.)

This approach works better with Sonador's long term plans and offers more flexibility. Authentication and authorization should be moved to the Python plugin.