Access external blob store in webviz application

[HansKallekleiv]

• As a plugin developer I want to deploy a single, multi-user, centralized app that can mount and read data from an external Azure blob store.
  I want to access the blob store as a folder structure, and use e.g. glob operations in python to list files and extract/aggregate data into python objects that can be visualized in dashboards.
• The webviz application should detect changes to the blob store files and refresh its content.
• All users that has access to the webviz application will have equal access to the blob store (all or nothing).