UX Design: https://docs.google.com/document/d/1_ztfMPQc8SYXyE65fywHqCAJbYToPEsnCkRTjiHB234/edit?usp=sharing

Implement the KCP workspace switcher. This component appears below the masthead on pages that have a workspace context. It is needed for both hac-dev and hac-infra, but ultimately we want it to be usable by other ConsoleDot tenants such as Kafka. We want to make workspaces a general way of organizing resources into buckets for our managed services.

We need to collaborate with the ConsoleDot team to understand where the component needs to live such that other tenants can use it.

The workspace switcher will need to know the current application context in order to bring workspaces with those APIs to the top. This also depends on KCP either labeling those workspaces or giving us some way to efficiently know what services are available without making individual requests for each workspace.