Geo - Convert Designs API to GraphQL

What/Why

Related to #219402 (closed)
Follow up from !32872 (closed)

As part of implementing Package Files (via GraphQL) into the Geo frontend we have to support REST and GraphQL via the same UI components. This has caused quite a bit of conditional code that has been needed to be added. The main reason for this, is Designs is still served via REST.

Once this occurs we can then remove all REST support and conditional code from the Geo Replication UI (#219417 (closed)).

Proposal

Add Designs as a GraphQL endpoint, supporting all existing REST functionality
Update frontend to use GraphQL patterns implemented as part of !32872 (closed)
Take into consideration #219402 (closed) when implementing
Take into consideration #219942 (closed) when implementing

cc: @mkozono