[charts] Add 'series' trigger to tooltip

[bernardobelchior]

Add 'series' trigger to tooltip. For now, it will only work for radar series.

I've kept the 'item' trigger working so we can cherry-pick this change to v8 to ease migration. I'll remove the 'item' trigger for the radar in a follow-up.

[mui-bot]

Deploy preview: https://deploy-preview-21656--material-ui-x.netlify.app/

Updated pages:

• docs/data/charts/radar/radar.md
• docs/data/charts/tooltip/tooltip.md

Bundle size report

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-premium	0B(0.00%)	0B(0.00%)
@mui/x-charts	🔺+736B(+0.20%)	🔺+99B(+0.09%)
@mui/x-charts-pro	🔺+736B(+0.15%)	🔺+134B(+0.09%)
@mui/x-charts-premium	🔺+736B(+0.15%)	🔺+142B(+0.10%)
@mui/x-date-pickers	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers-pro	0B(0.00%)	0B(0.00%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	0B(0.00%)	0B(0.00%)

Details of bundle changes

Generated by 🚫 dangerJS against 0f63985

[codspeed-hq]

Merging this PR will not alter performance

✅ 14 untouched benchmarks

---

_{Comparing bernardobelchior:bernardobelchior/radar-series-tooltip (0f63985) with master (9749b4c)¹}

Footnotes

1. No successful run was found on master (3b1a367) during the generation of this report, so 9749b4c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[github-actions]

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