[Feature] Flatten Revenue By Geography and Business Line

[deeleeramone]

1. Why?:

   • The nested response is incompatible with the Excel add-in.

2. What?:

   • We flatten the object and return in the style of a pivot table.
   • Remove unnecessary query parameter - "structure".
   • Move "period" from the standard model to the FMP model.

3. Impact:

   • Breaking changes:
     • The response object is now a flat list of records.
     • No more "structure" parameter.
   • Improved response object and better cross-product compatibility.

4. Testing Done:

   • Unit/integration tests.

[montezdesousa]

lgtm