Resolves hackoregon/civic-devops#244 for two of the five 2017 API services, and provides a working pathway to begin addressing hackoregon/civic-devops#238.

Converts two non-identical ECS services from EC2-based deployment to Fargate-based deployment.

These two Django APIs have dissimilar configurations (e.g. one logs its incoming requests to CloudWatch, the other does not), and have been migrated to Fargate tasks such that:

• Listener priorities are preserved (note: this doesn't generally work when replacing directly - I had to do some interim juggling by setting the new Fargate tasks to different Listener priorities, so that the existing ones would drain, and then reset the Listener priorities for the new Fargate tasks back to their original values)
• a Task Execution role is now defined as part of the ECS cluster that provides the ECS Fargate tasks the same level of access to AWS as the ECS EC2 services have
• a new security group is defined for access to the ECS Fargate Tasks
• TaskCpu, TaskMemory, ECSTaskExecutionRole, SecurityGroup and Subnets configurations are passed into the Fargate services from the master template

We are taking the opportunity - as part of our goals this season to reduce the AWS costs for our "staging" deploys - to reduce the number of container instances (Tasks) deployed in Fargate to 1 from the 2 that we have always deployed for every container since 2017.