Refactored app template review

[farski]

See PRX/internal#696. Provide the results for this app in this issue.

[cavis]

• [x] CPU and memory for all task definitions
• [x] Desired count for all ECS services
• [x] Correct listener rules and priorities
• [x] All tags
• [x] Stack description
• [x] Log group retention
• [x] Alarms (missing alarms, unnecessary alarms, incorrectly configured alarms, etc)
• [x] Alarm names and descriptions
• [x] Look for anything that look problematic for multi-region (e.g., hard-coded regions, etc)
• [x] Environment variables moved from secrets to the template
• [x] Target group health checks and deregistration values
• [x] Missing resource/components (compare to old template)
• [x] TODOs and tktk