Add support for portMappings

[erichcarson]

Add support for portMappings as part of the AWS::ECS::TaskDefinition.

Verification:

• Updated unit tests and added portMappings.
• Used this branch with my projects serverless.yml to successfully deploy a task with the correct exposed ports.

  tasks:
    my-task:
      image: my-image
      memory: "0.5GB"
      cpu: 256
      architecture: ARM64
      portMappings:
        - containerPort: 3478
          hostPort: 3478
          protocol: "udp"
        - containerPortRange: "10000-20000"
          protocol: "udp"

[erichcarson]

Ping @eddmann.

[linuxmant]

This would be great to have

[eddmann]

Thank you for the PR 🙏🏻 , apologies for the current merged/revert, I was just garnering additional insight into this. Just wondering can this not already be achieved with the cloudFormationResource extension property?