[Indexing Strategy] Change stream.* to dataset.* fields

[ruflin]

In #482 it was discussed and decided to move from stream.* fields to dataset.* fields. This issue is to track the changes across all the different affected parts across the stack.

• Change code in https://github.com/elastic/integrations repo to create correct fields and adjust migration script (for example dashboards) (@mtojek ) Update dataset in packages integrations#64
• Adjust package registry to validate correct fields (@ruflin ) Update registry for stream.* to dataset.* change #492
  * [ ] Update package format to use the correct terms in the manifest (@ruflin )
• Update Elastic Agent to change enrichment processors (@michalpristas ) [Ingest Manager] Moved from stream to dataset beats#18967
• Adjust Ingest Manager to understand changed fields in package format (@jen-huang)
  • (Jen) I believe no changes needed, pending investigating in the PR below
• Update queries in Ingest Manager to use new code (@jen-huang) [Ingest Manager] Update queries from stream.* to dataset.* kibana#68322
• Update indexing strategy docs (@ruflin ) [Ingest Manager] Update indexing strategy docs to use dataset.* kibana#68068
  * [ ] Update code in Endpoint agent to enrich correct fields (@ferullo )  (not used yet)
• Discuss to get fields into ECS (@ruflin ) [Meta] Add ECS Dataset fields ecs#845
• Update existing packages in package-storage (@ruflin) Add dataset fields to all packages package-storage#56

It might be that some of the above changes will be breaking and a sync is needed between teams to get them merged at the same time.