Modify first line of report to have basic columns

[jberenhaus]

When importing into PowerBI, there are no columns. We can do a partial definition (since we can't name all columns due to the ability to make custom recipes) by just adding the default names of columns to the first line.

It should look something like:
Browser, UA Hash, Url, Timestamp, (blank), Logging Source, Recipe Name, (blank for the rest since it's keys and values)