ECS Task: Enable security groups

[BadAsstronaut]

I would like to pass an existing Security Group(s) to enable communication between Orion and generated ECS tasks and other network-isolated services in my VPCs.

[zanieb]

Can you share an example of where these would be passed?

[BadAsstronaut]

https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_RunTask.html
This is another NetworkConfiguration option, so probably similar to #113 and #112

Additionally, we should be able to disable assignPublicIp.