[FEATURE] Multi-account ECS blueprint

[arvindsoni80]

Is your feature request related to a problem? Please describe

Account level security access control

Describe the solution you'd like

Customers commonly use multiple accounts for e.g. -/ one account for CI/CD shared services -/ account for test/staging cluster -/ production account. This blueprint will define multi-account setup to use for running containers on ECS. Following is the desired account structure:

1. CI/CD and associated services in one account
2. an account with test cluster and test ECR images
3. an account with production cluster and production ECR images

Make the blueprint flexible so that it is easier for customer to add more accounts for e.g. staging, Q/A etc. The designer should review AWS Control Tower, AWS Organization and landing zone best practices to align with the latest well-architected for multi-account setup.