add `datasets` column to `network` tab

[ramfox]

This column should pull from the newly made /registry/list api endpoint, which returns a list of the dataset summaries available on the registry.

• [x] create new actions/registry.js file
• [x] add registry section to entities
• [x] add action to pagination
• [x] create action that calls to /registry/list

  REGISTRY_DATASETS_REQUEST
  REGISTRY_DATASETS_SUCCESS
  REGISTRY_DATASETS_FAILURE

• [x] create new selectors/registry.js file
  • [ ] selectNetworkDatasets func => selects ids from pagination and gets datasets from entities
• [x] select datasets in network container
• [x] add datasets list component to network component

[ramfox]

Take a look at #426 for updates and changes to this design!