Copilot-cli: Task Run Improvements

[kohidave]

Now that we have task run (wooo), I think there are a few things we can do to smooth the experience a bit!

• [ ] Create a default cluster if there isn't one, and the customer selects default
• [ ] Speed up the Provisioning Task Resources step
  
  
  
  • [ ] Related, we might want to create one ECR repo for run tasks named copilot-task-run otherwise you end up bumping up to naming issues if your pwd is named something with a dash in it. Alternatively, remove the dash from the ECR repo name.
  
  
• [ ] Make --follow the default
• [x] Stop following a task when it's status becomes stopped (right now --follow hangs)
• [x] Remove ✔ Successfully provisioned task resources. line
• [ ] If no Dockerfile is present, and no --image flag is provided, we should default to amazonlinux image.
• [x] When a task launches, it'd be awesome to show its IP address.
• [x] Allow customers to pass in a --svc flag which uses the service's task role (proposal is at #2159)

[aviflax]

Remove ✔ Successfully provisioned task resources. line

Why remove this?

Personally when I copy-and-paste a terminal session, e.g. for a bug report, or perhaps an experience report, a presentation, etc — I’d prefer to have the entire user experience recorded there and clearly apparent. That feels, to me, more intuitive with a CLI tool.

(It does seem that the team might be going for a more interactive/dynamic “feel” for the tool, as compared to most CLI tools, which is definitely cool, but might have some downsides. Maybe those of us who want to use a CLI tool like the way CLI tools tend to work, and would prefer that the more interactive/dynamic approach be limited to GUIs.)

[aviflax]

Suggestion, as per this comment on #1432:

```diff
- Allow customers to pass in a --svc flag which uses the service's task role (see #1432)
+ Allow customers to pass in a --svc flag which uses the service's task role, env vars, and secrets (see #1432)

[efekarakus]

I'm super excited to announce the new --generate-cmd flag available to task run to spin up a one-off task from an existing ECS service! https://github.com/aws/copilot-cli/releases/tag/v1.7.0