The "fetch" library should allow for Capabilities metadata to be fetched after a standard REST API call is made, so a unified view of the data can be returned to the UI component layer.

Need to design a configuration that can be passed to fetch to indicate which graph paths in the response should be used for fetching capabilities.

e.g. for the following response

[
    { name: 'pipeline', _class: 'io.jenkins.blueocean.rest.model.PipelineImpl' },
    { name: 'freestyle', _class: 'io.jenkins.blueocean.rest.model.AbstractPipelineImpl }
]

we need a way to express that the top-level "_class" property should be fetched. Perhaps GraphQL can be used as an inspiration for this if not outright implementation.

The augmented response would look like:

[
    { name: 'pipeline', _class: 'io.jenkins.blueocean.rest.model.PipelineImpl', _capabilities: ['foo.bar.Thing'] },
    { name: 'freestyle', _class: 'io.jenkins.blueocean.rest.model.AbstractPipelineImpl, _capabilities: ['foo.bar.OtherThing'] }
]