Display message on submit page if sample collection does not exist

[gfrn]

Summary:

Previously, an error was thrown if a user manually changed the URL to point to a sample collection which did not exist in the submitted page. This now displays an error message and a link back to the dashboard.

Changes:

• Display message on submit page if sample collection does not exist

To test:

• Go to https://local-oidc-test.diamond.ac.uk:9000/proposals/bi23047/sessions/100/shipments/999999/submitted (or any invalid sample collection/shipment) and check if "sample collection unavailable" is displayed

[ndg63276]

LGTM