[Lens] Revisit Random sampling UI

[dej611]

Summary

Follow up from #143221

Updated with @MichaelMarcialis feedback PR.

Changes summary:

• Switch the slider's EuiFormRow from columnCompressed to rowCompressed to allow the slider to expand to the full available width of the flyout.
• Show "Speed" and "Accuracy" labels at each of the slider's respective extremities to emphasize what is happening.
• Change the slider's tick numbers to percentages for easier reading.
• Update help text below the slider to briefly explaining what this feature does (supplied by @KOTungseth) and include a link to the full documentation.

Revisited UI design as discussed with @MichaelMarcialis .
Created a copy stub for the help text @KOTungseth

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
• 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

Risk Matrix

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Before closing this PR, invite QA, stakeholders, and other developers to identify risks that should be tested prior to the change/feature release.

When forming the risk matrix, consider some of the following examples and how they may potentially impact the change:

Risk	Probability	Severity	Mitigation/Notes
Multiple Spaces—unexpected behavior in non-default Kibana Space.	Low	High	Integration tests will verify that all features are still supported in non-default Kibana Space and when user switches between spaces.
Multiple nodes—Elasticsearch polling might have race conditions when multiple Kibana nodes are polling for the same tasks.	High	Low	Tasks are idempotent, so executing them multiple times will not result in logical error, but will degrade performance. To test for this case we add plenty of unit tests around this logic and document manual testing procedure.
Code should gracefully handle cases when feature X or plugin Y are disabled.	Medium	High	Unit tests will verify that any feature flag or plugin combination still results in our service operational.
See more potential risk examples

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/kibana-vis-editors @elastic/kibana-vis-editors-external (Team:VisEditors)

[MichaelMarcialis]

Hey, @dej611! Thanks for making these changes. I've opened up a quick PR in your repo containing all of my design suggestions. Please give that a look when you get a moment. Once approved and merged, I can approve this PR.

[dej611]

@MichaelMarcialis I wasn't sure of the EuiBetaBadge and whether it was universally recognized as Technical Preview , reverting to its long version of it. I saw you've used it, so I guess it's ok to use it to indicate also for the future.
Do you think it is worth to revisit the badge also in other contexts (like the chart switcher)?

[MichaelMarcialis]

@MichaelMarcialis I wasn't sure of the EuiBetaBadge and whether it was universally recognized as Technical Preview , reverting to its long version of it. I saw you've used it, so I guess it's ok to use it to indicate also for the future.
Do you think it is worth to revisit the badge also in other contexts (like the chart switcher)?

I think in most cases, we should use EuiBadge with the full Technical preview text. In certain circumstances (such as this) that require a smaller and less prominent badge, I think it's OK to switch to the EuiBetaBadge with icon. So I'd recommend we leave the chart switcher as is for now.

[MichaelMarcialis]

Thanks for merging in those changes. Looks good to me!

[drewdaemon]

LGTM code review only

[mbondyra]

Nice new feature (just reviewing this and the previous merged PR to notice the change) 👌🏼

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 935cc60

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
lens	1.3MB	1.3MB	+947.0B

History

• 💚 Build #82727 succeeded 2160aa3
• 💚 Build #82428 succeeded 4ed0198

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

[dej611]

Talked offline with @KOTungseth : will merge this now and a PR with docs changes will follow up if required