[Lens] Reverse colors should not reverse palette picker previews

[dej611]

Summary

Fixes #110290

This PR is an attempt to address the #110290 problem, while changing a bit the palette panel behaviour:
when revering a color stops configuration, this PR makes an automatic transition of the palette from the current state to a custom palette.

This means that the current saved palette configuration with predefined palettes and reverse option should be migrated to the new configuration.
Because the palette picker is now showing predefined palettes always with a direction, selecting one of these palettes resets the reverse flag.

• On reverse transition to a custom palette
  • It would be nice to have the picker popover scroll to the current selection
• On new palette selection from the palette picker resets the reverse flag
• add a migration script to handle the new reverse state

Testing

• Create a new datatable and with a predefined palette reverse the color stops

  • Check on the palette picker that all palettes have not been reversed and the current selection is now the Custom Palette

• I've prepared a dashboard with 4 datatables using conditional coloring with a predefined palette (2 reversed + 2 regular) before the fix/migration (rename the extension from txt to ndjson and import it)

  • Exported SO: preDatatableFix.txt

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

Risk	Probability	Severity	Mitigation/Notes
Migration should correctly work on current user datatables/heatmaps	Medium	Medium	Unit tests will verify that migration will touch only specific datatables and heatmaps affected by the issue.

[dej611]

@elasticmachine merge upstream

[elasticmachine]

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

[nreese]

maps changes LGTM
code review

[mbondyra]

@elasticmachine merge upstream

[mbondyra]

@dej611 thanks for preparing testing saved objects. I tested by migrating the provided samples and my own SO (screenshot) too, just to be sure. Tested on Chrome and migrations work as expected.

Code LGTM

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 0653ed3
• Storybooks Preview

Metrics [docs]

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
lens	228	229	+1

Async chunks

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

id	before	after	diff
lens	1.6MB	1.6MB	-191.0B

Unknown metric groups

API count

id	before	after	diff
lens	246	247	+1

History

• 💛 Build #150977 was flaky e6d205c
• 💔 Build #150881 failed 2cde630
• 💔 Build #150637 failed 9a98071
• 💚 Build #149389 succeeded af5ef2a

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

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.x

This backport PR will be merged automatically after passing CI.