[Security Solution] [Sourcerer] useFetchIndex unified data source access

[dhurley14]

Once this PR has merged, #149360 the security solution should no longer need to rely on component-level state and effects to determine whether it is safe to access certain properties on the specific data source, as all data sources are now typed to be data views, whether you pass in an array of index name strings or a data view id. My ask will be to update all components where we are separately fetching a data view (if a component receives a data view id) and setting associated state within that component and remove those useEffect hooks and associated state and rely on the data view provided by useFetchIndex.

For example, this:

kibana/x-pack/plugins/security_solution/public/detections/components/rules/step_define_rule/index.tsx

Lines 289 to 319 in 2225de0

	const [isIndexPatternLoading, { browserFields, indexPatterns: initIndexPattern }] = useFetchIndex(
	index,
	false
	);
	const [indexPattern, setIndexPattern] = useState<DataViewBase>(initIndexPattern);
	const { data } = useKibana().services;
	// Why do we need this? to ensure the query bar auto-suggest gets the latest updates
	// when the index pattern changes
	// when we select new dataView
	// when we choose some other dataSourceType
	useEffect(() => {
	if (dataSourceType === DataSourceType.IndexPatterns) {
	if (!isIndexPatternLoading) {
	setIndexPattern(initIndexPattern);
	}
	}
	if (dataSourceType === DataSourceType.DataView) {
	const fetchDataView = async () => {
	if (dataViewId != null) {
	const dv = await data.dataViews.get(dataViewId);
	setDataViewTitle(dv.title);
	setIndexPattern(dv);
	}
	};
	fetchDataView();
	}
	}, [dataSourceType, isIndexPatternLoading, data, dataViewId, initIndexPattern]);

Can now just become:

const [isIndexPatternLoading, { browserFields, indexPatterns: dataView }] = useFetchIndex( 
   dataViewId ?? index,
   false 
 );

[elasticmachine]

Pinging @elastic/security-solution (Team: SecuritySolution)