Enrich alert emails with query context

[erikdarlingdata]

Migrated from erikdarlingdata/Monitor#29

Current Behavior

Alert emails are missing useful query context:

Deadlock alerts

• Currently: Only includes victim query text
• Needed: Include winner/survivor query text too — knowing what killed you is only half the story

High CPU alerts

• Currently: Just reports the CPU percentage
• Needed: Include top 3 CPU-consuming queries at time of alert

Memory alerts

• TBD: Investigate what the current memory alert triggers on and whether memory grant information (query text, requested/granted memory) should be included

Expected Behavior

Each alert email should contain enough context that a DBA can start investigating without having to open the dashboard.

[erikdarlingdata]

Closing in favor of a centralized Alerts History view in the Dashboard UI, which solves the same problem (quick assessment of alert context) without the security concern of query text in emails. See new issue.