Alter id on EuiFormRow wrapping element

[thompsongl]

Summary

Work in #2569 highlights a case where EuiFormRow can improperly render multiple elements with the same id. This only happens when an id is directly passed to EuiFormRow ( id remains part of ...rest). Regardless, the cloned child form control is the intended target for the id, not the wrapping element.

Options:

1. Remove id from the wrapping element entirely (what I've currently done)
2. Create a new id (e.g., ${id}-row) so the wrapping element is still referencable (what's currently done)
3. ???

I think it's likely that comprehensive axe analysis would find more than just the one case highlighted in #2569, especially in Kibana.

Checklist

- [ ] Checked in dark mode
- [ ] Checked in mobile
- [ ] Checked in IE11 and Firefox
- [ ] Props have proper autodocs
- [ ] Added documentation examples

• Added or updated jest tests
• Checked for breaking changes and labeled appropriately

- [ ] Checked for accessibility including keyboard-only and screenreader modes

• A changelog entry exists and is marked appropriately

[myasonik]

Any concern that there's now no way to pass an ID to EuiFormRow?

Also, does this constitute a breaking change? (Someone could be expecting the ID on either element to do some hacky things...)

[cchaos]

I agree with @myasonik, I think we should keep an id on the form row but append -row or something to it. This would definitely be a breaking change as it could break some functional tests.

[thompsongl]

I can work on Option 2 👍

[myasonik]

🤞 This doesn't make updating Kibana a huge pain...

[thompsongl]

Snapshot changes in Kibana appear to be all additions, so that's good. Any functional test failures caused by this will point towards places where data-test-subj should've probably been used instead.