ui: create node pool model

[ChaiWithJai]

Resolves #17292

This PR adds a new NodePool model and serializer. The NodePool model is used to represent a pool of nodes that can be used to run applications. The serializer is used to serialize the JSON response of a NodePool object to a JSON:API object.

The NodePool model has the following properties:

name: The name of the node pool
description: A description of the node pool
meta: A map of additional metadata about the node pool
schedulerConfiguration: The configuration of the scheduler for the node pool

The serializer serializes NodePool objects to JSON:API by converting the properties of the objects to strings. The following is an example of the serialized object that is generated for a NodePool object:

{
  "name": "prod-eng",
  "description": "Production workloads",
  "meta": {
    "env": "production",
    "team": "engineering"
  },
  "schedulerConfiguration": {
    "SchedulerAlgorithm": "spread" // pattern match:  We don't apply camelCasing for nested objects in other models
  }
}

[github-actions]

Ember Test Audit comparison

	main	f2fc72a	change
passes	1478	1493	+15
failures	0	1	+1
flaky	0	0	0
duration	12m 12s 024ms	000ms	-12m 12s 024ms

[lgfa29]

Looking great!

I think removing the all node pool from the client list dropdown is the main blocker, otherwise you would always get an empty list result.

It would nice to have the topoviz updates as well, since it's such a useful page 😄