Add new processing directories to distribution

[mandy-chessell]

Description

This PR updates both the distribution and the docker published by the merge/release workflows to:

• move the content packs under platform so that they are available in the docker image.
• add directories for the integration daemon to work against in the docker image:
  • sample_data includes our standard set of sample data files - this is catalogued by the SampleDataFilesintegratorConnector.
  • landing_area is a free space to allow users to add files to be catalogued. In the docker invironment this can be one of the external mount points so new files can be catalogued by the integraiton daemon.