Filter and copy values from the Discover table JSON view

## Summary

The Discover table JSON view now lets you filter by a leaf value, including one value of a multi-value field. Filtering is not offered for values inside a parsed flattened field or a parsed JSON string. The cell adds a Copy all button. Command-click expands nodes recursively. Pagination now shows the total sibling count, and wrap-lines mode truncates very long values at 100 lines.

**Why this needs docs:** Discover docs already cover flyout filters and copy-as-JSON for selected rows, but they omit the in-table JSON tree actions users would miss.

## Resources

- PR [#286819](https://github.com/elastic/kibana/pull/286819) — [Discover][Table] Json view enhansements
- PR [#282282](https://github.com/elastic/kibana/pull/282282) — [Discover] [Table] Integrate `JSONTreeViewer` in Discover
- Product issue: https://github.com/elastic/kibana/issues/284302

Screenshots from PR


## Availability

| Channel | Details |
|---------|---------|
| **Stack** | v9.6.0 |
| **Serverless** | Aug 31–Sep 4 |
| **Feature flag** | has |

---
*Created with [Docs Quest Scanner](https://github.com/florent-leborgne/docs-quest-scanner) by @florent-leborgne*

## Suggested edits

[Explore fields and data with Discover](https://www.elastic.co/docs/explore-analyze/discover/discover-get-started) > Explore individual result or document details in depth
- **What the docs say:** The section describes the document flyout. Users filter from Field or Value columns. A later section copies selected rows as JSON. Neither describes the in-table JSON tree.
- **What to add:** Add a short subsection for the table JSON view. Document filter-by-leaf-value, the limit on flattened and parsed JSON strings, Copy all, and Command-click to expand nested nodes. Skip the pagination count and 100-line truncation unless you already document wrap-lines. Applies from 9.6.0 and in serverless.