feat(iroh-cli): add doctor plot

[Arqu]

Description

Allows for quick plotting of prometheus style metrics. By default it looks at http://localhost:9090 but can be configured.
When the plotter app is active you can freeze the state by pressing f or quit by pressing q.
A magic metric named random can be used for demo purposes and simply generates a 1-100 value on every tick.

Sample usage:
iroh doctor plot magicsock_relay_home_change_total,iroh_requests_total_total,random

Still got some cleanup to do and some sanity checking so we don't blow up in some cases.

Notes & open questions

Change checklist

• Self-review.
• Documentation updates if relevant.
• Tests if relevant.