Replacement for User Misery / Apdex

### Problem Statement

* User Misery based on LCP doesn't work for all web browsers.
* What constitutes _a miserable user experience_ varies by type of transaction: backend, vs., frontend.

We would like a measurement that acts as a good sorting key for each domain, Frontend, Backend, Mobile, and AI, helping users pick the most important spans to spend time optimizing for performance.

### Solution Brainstorm

**Option 1: Show Time Spent universally across performance views as the last column**

_Time Spent_, which we show on Insights pages, may be a good option.

**Option 2: Extend user misery**

Add additional options for user misery, allowing perhaps:

1. A custom EAP query to be used for the user misery column.
2. Add Apdex as one of the sorting options for user misery.

### Product Area

Insights