URO-82, URO-168 Add share narrative function.

[dakotablair]

This PR adds the API calls for updating sharing in the narrative control menu. This is also the final piece of functionality for the Navigator as a whole. That is, no major new functionality remains for Navigator itself. In particular, the narrative navigator is now feature complete.

• URO-82: Create Navigator Component
  • Aligns roughly to mockup URO-78.
  • Implement user behaviors existing in previous Navigator
  • Manages state for searches and filters
  • Manages quantity of search results displayed
  • Manages state for the control menu including
    • delete
    • copy
    • link (to an organization)
    • rename
    • restore
    • share
  • Handles narrative metadata changes at least to the standard of the previous Navigator
• URO-168: Add API calls to the Share Narrative action in the control menu.
  • Narratives can be shared (Narrative permissions of a specified level can be assigned to a specified user) using the Narrative Control Menu. Specifically narrative admins may:
    • Add a new user with selected permissions
    • Remove a user from shares
    • Update a user's permission level
    • Make a narrative globally public or private
  • If the action fails then this is shown to the user using a toast notification. Have distinct messages for when:
    • The app cannot confirm action success.

[dauglyon]

minor comments, but everything LGTM