[Logs UI] Add pagination to embeddable <LogStream /> component

[afgomez]

Summary

Add pagination capabilities to the <LogStream /> embeddable component

Acceptance criteria

• The <LogStream /> will have a paginable prop.
• The component will fetch previous pages (if available) when reaching a certain top scroll threshold.
• The component will fetch next pages (if available) when reaching a certain bottom scroll threshold.
• Documentation has been properly updated.

[elasticmachine]

Pinging @elastic/logs-metrics-ui (Team:logs-metrics-ui)