Support Uptime Monitor for % Monthly Uptime on Insights Uptime Page

### Problem Statement

Currently you can see all your uptime monitors on Insights.Uptime but you have to open each one individually to see the % Monthly Uptime.

**Ask:** "How can I see in a report form (or dashboard) a view of all uptimes at once?
**Motivation:** "Management wants to review, I want to present to Management"

### Solution Brainstorm

**Idea1**
Add a column to Insights.Monitors showing % Monthly Uptime. https://demo.sentry.io/insights/uptime/?project=-1&statsPeriod=90d

**Idea2**
I'm not sure adding Dashboard Widget support for Uptimes would help, because I'm not sure it would show % Montly Uptime. Anyone know?
https://github.com/getsentry/sentry/issues/90607

### Product Area

Alerts

Start with the Insights.Monitors uptime view described in the issue and review the related dashboard-widget discussion in issue #90607. No files or tests are named, so first confirm whether the requested report is a Monthly Uptime column or a dashboard widget, then define acceptance criteria for showing all monitor percentages together.

Written by the indexing model from the issue text.