Remove references to the old Registry, refer to Datasets instead of File names, upgrade deps

[simon-20]

This PR will:

• Remove references to the old Registry, resolving Validator web still refers to IATI Registry #987
• Use dataset short name rather than file URL, resolving Use dataset name, rather than "file name" on organisation listing pages #229
• Upgrade some of the dependencies with security alerts

[simon-20]

The tests that are failing are failing because the Validator frontend CI runs against the dev instance of validator-services, which uses the unified platform dev database, and that database is full. I'm resolving that issue, at which point the tests here should start passing again.