Load Data: Add flux sources to the load data page

[russorat]

right now, we have a feature flag: influx.set("load-data-flux-sources", true) which will add a Flux Sources area to the app:

The goal of this issue is to add Flux sources to this page so that a user searching that page would see flux sources as an option.

Let's start with the sql sources: https://docs.influxdata.com/influxdb/v2.0/reference/flux/stdlib/sql/from/#examples

The expectation is that someone clicking on a "Flux From MySQL" data source, would be dropped into a flux script editor with the example populated. For example: