Support Uptime Monitor Widgets on Dashboards

### Problem Statement Currently, Uptime Monitor data cannot be added to Sentry Dashboards. This limits teams, especially non-engineering teams like customer support—from viewing overall app health alongside other key metrics. ### Solution Brainstorm - Add Uptime Monitors as a supported widget type. - Allow basic uptime metrics (e.g. availability, incidents) to be displayed. - Enable customization similar to other widgets (filter by tag, environment, etc.). ### Product Area Dashboards