Information architecture and Dashboard UX improvements

### Required Terms

- [X] I agree to follow this project's [Code of Conduct](https://github.com/heroku/roadmap/blob/main/CODE_OF_CONDUCT.md)
- [X] I have read and accept the [Salesforce Program Agreement](https://www.salesforce.com/company/program-agreement/)

### What service(s) is this request for?

Dashboard, cli

### Tell us about what you're trying to solve. What challenges are you facing?

Currently, Heroku Dashboard (the web UI) is very app-focused, eg. it's typically navigated through lists of apps (by team, personal apps, etc.). The other organizing constructs are Private Spaces and Pipelines, which help somewhat. Search functionality has also helped quickly navigate the contents of Heroku accounts.

Customers have requested more ways to navigate what they're running on Heroku, eg. by domain/hostname associated with apps.

Opening this issue to gather more ideas and feedback for Heroku Dashboard improvements.