[ML] Single Metric Viewer embeddable: show error message when insufficient permissions

[alvarezmelissa87]

Summary

When the user does not have enough permissions, ensures that the single metric viewer panel in dashboards shows an error message (similar to the other ML dashboard panels) instead of just being blank.

Before:

After:

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• Flaky Test Runner was used on any tests changed
• Any UI touched in this PR is usable by keyboard only (learn more about keyboard accessibility)
• Any UI touched in this PR does not create any new axe failures (run axe in browser: FF, Chrome)
• If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser)
• This was checked for cross-browser compatibility

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[qn895]

Code LGTM 🎉

[peteharverson]

Tested, and other than the suggested edit for the error text on the three ML embeddable panels, LGTM

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 8567d07

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
ml	4.1MB	4.1MB	+449.0B

History

• 💔 Build #204143 failed cc1826f
• 💚 Build #203863 succeeded d4f2101

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @alvarezmelissa87