Add a feedback command to ecctl

@ppapapetrou76 commented on [Tue Aug 27 2019](https://github.com/elastic/cloud-cli/issues/982)

I was playing with azure-cli and there's a nice command `az feedback` with the following output

```$ az feedback

We appreciate your feedback!

For more information on getting started, visit: aka.ms/azcli/get-started
If you have questions, visit our Stack Overflow page: aka.ms/azcli/questions

Recent commands:

[0] create a generic issue.
[1] az login : SUCCESS. Ran: 1 mins ago.
[2] Unknown (help) : SUCCESS. Ran: 39 secs ago.

Enter the number of the command you would like to create an issue for. Enter q to quit: q
```

It's an interactive way of submitting a bug or a feature request for a specific command or a generic issue.

I believe it's a nice feature to add to our own cli

---

@marclop commented on [Fri Jan 03 2020](https://github.com/elastic/cloud-cli/issues/982#issuecomment-570520797)

This is pretty cool, I think we can accomplish something similar with what we already have, we need to record execution:

* Obtain the command which is going to be executed.
* Record the command execution time.
* Save the contents in a format which can be consumed by `ecctl feedback`.
* Add a global flag which allows toggling the usage of telemetry.
* Tie it with a template on which to provide feedback and https://github.com/elastic/ecctl/issues/new?labels=area%3Atooling&template=FEEDBACK.md