Shorten the route for shipment info to remove the queue name

[chrisgilmerproj]

Description

This has bugged me for a while. The way to get to a shipment should always be independent of the queue its associated with. This will make more sense when we also have the shipments/:shipmentId/documents and shipments/:shipmentId/documents/:moveDocumentId routes.

Code Review Verification Steps

• End to end tests pass (make e2e_test).
• Request review from a member of a different team.

[chrisgilmerproj]

I think e2e tests would work if the branch was built on this: https://github.com/transcom/mymove/pull/1019/files

[jim]

@chrisgilmerproj Code looks good.

I believe that originally there were some next/forward controls to move within a queue on the shipment page, which was probably the original impetus for those URLs.

We don't have those, though, so I say go for this simplification.