Design a Grafana dashboard panel to visualise per-user costs

[jnywong]

Context

Hub admins can interact with per user costs with Grafana, a front end visualisation tool. We need to design and deploy a dashboard to enable this.

Definition of Done

• Outline a dashboard design
• Update cost monitoring backend as needed
  • Add component endpoint jupyterhub-cost-monitoring#29
  • [Grafana] Handle "all" when passed through dashboard variable jupyterhub-cost-monitoring#30
  • more to follow in Iterate given lessons learned from User cost monitoring prototype #6649
• Write basic user facing documentation
  • [docs] jupyterhub-cost-monitoring#39
  • Add how to guide for cloud costs per user dashboard docs#269
• Present dashboard for feedback
  • maap
  • openscapeshub
  • earthscope
    • pending activation of costs tags https://2i2c.freshdesk.com/a/tickets/3789
  • 2i2c-aws-us (internal)

[jnywong]

Breaking off the last task into its own issue for the next sprint: #6658