[OneDiscover] DataTable log.level colored badge cell renderer

[kertal]

📓 Summary

To indicate the log.level severity in Discover, the UnifiedDataTable should render values of the field log.level as a badge in a configured color that match the colors of the severity indication on the left side of a table row (https://github.com/elastic/kibana/issues/186264).

To be defined: log.level values (there can be multiple different values for a severity level like err or error) to displayed colors table

✔️ Acceptance criteria

• Create a custom cell renderer for log.level, rendering a badge in a color that matches the severity of the level
• Make use of color indication in Logs Contextual Presentation

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)