Alert on Whatever (New, Ongoing) -> Escalating

### Problem Statement

Described here https://github.com/getsentry/sentry/issues/60542 but it didn't mention the "whatever" part — we only want to receive "escalating" event, hopefully with "escalating" in the email subject as well.

### Solution Brainstorm

_No response_

### Product Area

Alerts