[discuss][Drilldowns][URL drilldown] Expose "event.row" in VALUE_CLICK_TRIGGER

[Dosant]

Summary

Problem

Consider the table:

With current variables setup when drilling down in to cell in the table (e.g. "Venice") it was not possible to access data from the whole row. (No access to "IT" or "4").

Solution

This pr exposes {{event.row}}.

And it allows to build a URL that uses the whole row:

Caveats

1. Because of how preview with mock variables work, I had to weaken the validation for saving the Drilldown. number of items in row could be large and we won't cover all this variables with mocks. to be able to save something like: {{event.row.[100]}} I had to weaken editor validation. In runtime it still won't be compatible if variable is not available. [discuss][Drilldowns] More specific triggers and trigger context samples #76226

2. Do we need anything else to be exposed? Columns? Clicked rowIndex? columnIndex? In what format?

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
• This was checked for keyboard-only and screenreader accessibility
• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser
• This was checked for cross-browser compatibility

For maintainers

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

[elastic-jb]

This looks really good. Is there something we can do to respect the formatting on the chart or should we add a helper for formatting decimal places?

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: e18ebbe

Metrics [docs]

page load bundle size

id	before	after	diff
uiActionsEnhanced	320.7KB	321.0KB	+397.0B
urlDrilldown	18.7KB	19.4KB	+698.0B
total			+1.1KB

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

[Dosant]

Is there something we can do to respect the formatting on the chart or should we add a helper for formatting decimal places?

I think we should consider adding a helper for this. #77758

[Dosant]

Discussed with @ppisljar:

Short-term this makes sense. But long-term it could be changed until we decide what exactly we want to do with this triggers. like, should we rather than index for columns use column names ? like row.count and row.city. but then this again needs us to know more about data when we are creating this ... (but not having this makes it easier to write invalid urls)

We agreed this should also be considered as part of spike about #76226 planned for 7.11

[elastic-jb]

This is definitely what we need.