insights: convert webapp just in time search insights to use insights graphql

Created by: chwarwick

As of #34149 the gql insightsViews now supports running just in time search insights. This means that all LineChart based insights data can be pulled via gql and the webapp no longer needs to maintain the separate logic to execute these queries.

Switching to using the gql enables just in time search insights to use the InsightViewFilters making that functionality available across all LineChart insight types.