[APM] Use index pattern service to load index patterns

[dannycroft]

There are a number of places where kibana index patterns are loaded directly from the Saved Object API instead of the index patterns service on the data plugin. This essentially treats the index pattern saved objects as an api in itself and makes changing the index patterns api more difficult. In particular, we'd like to be able to separate out the index pattern string from the displayed title of the index pattern. This issue tracks the changes needed to remove working directly with saved objects.

See: #91715

Example Files

• https://github.com/elastic/kibana/blob/main/x-pack/plugins/apm/server/routes/data_view/create_static_data_view.ts

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)