[DataViews] Evaluate switching ML alert rules to make use of DataViewLazy

[kertal]

When DataViewLazy is implemented (#167750), ML based alerting rules should be evaluated to consume this new class. The benefit of it is that it's no longer triggering a request for fields (field_caps request to ES) when being initialized. When fields are not needed, this saves a lot of redundant requests to Elasticsearch. At the first sight it seems the DataView service is needed to get the fieldFormatMap. For this the requests for fields should not be necessary:

kibana/x-pack/plugins/ml/server/lib/alerts/alerting_service.ts

Lines 217 to 234 in 50dabea

	/**
	* Attempts to find a data view based on the index pattern
	*/
	const getFieldsFormatMap = memoize(
	async (indexPattern: string): Promise<Record<string, SerializedFieldFormat> | undefined> => {
	try {
	const dataViewsService = await getDataViewsService();
	const dataViews = await dataViewsService.find(indexPattern);
	const dataView = dataViews.find(({ title }) => title === indexPattern);
	if (!dataView) return;
	return dataView.fieldFormatMap;
	} catch (e) {
	return;
	}
	}

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[elasticmachine]

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

[kertal]

@darnautov this should be unblocked now since DataViewLazy was merged: #173948