[Ingest Manager] Update queries from stream.* to dataset.* (#68322)

Resolves #67672

Part of elastic/package-registry#491

See elastic/package-registry#492 for package registry changes.

Updates existing queries to use `dataset.*` fields. from `stream.*` fields.

I looked at the EPM code paths for asset installation, and did not find anything that would need to be changed based on the above package registry changes. We don't hardcode anything specific for field names. The package information (i.e. [nginx package info](https://epr.elastic.co/package/nginx/0.1.2/)) is not affected by the current package registry changes.

x-pack/plugins/ingest_manager/server/routes/data_streams/handlers.ts

@@ -31,12 +31,12 @@ export const getListHandler: RequestHandler = async (context, request, response)
  must: [
  {
  exists: {
- field: 'stream.namespace',
+ field: 'dataset.namespace',
  },
  },
  {
  exists: {
- field: 'stream.dataset',
+ field: 'dataset.name',
  },
  },
  ],
@@ -54,19 +54,19 @@ export const getListHandler: RequestHandler = async (context, request, response)
  aggs: {
  dataset: {
  terms: {
- field: 'stream.dataset',
+ field: 'dataset.name',
  size: 1,
  },
  },
  namespace: {
  terms: {
- field: 'stream.namespace',
+ field: 'dataset.namespace',
  size: 1,
  },
  },
  type: {
  terms: {
- field: 'stream.type',
+ field: 'dataset.type',
  size: 1,
  },
  },

x-pack/plugins/ingest_manager/server/services/epm/elasticsearch/template/template.ts

@@ -388,12 +388,12 @@ const getIndexQuery = (templateName: string) => ({
  must: [
  {
  exists: {
- field: 'stream.namespace',
+ field: 'dataset.namespace',
  },
  },
  {
  exists: {
- field: 'stream.dataset',
+ field: 'dataset.name',
  },
  },
  ],