Validation: A fuel was reported for an Emission Category with no reported emissions

[dleard]

Our emission_category_missing_fuel() validation function checks for the opposite scenario where a (carbon taxed) Emission Category has reported emissions but a fuel was not reported for that category.

Question: do we need a validation for the scenario where a fuel is reported in a (carbon taxed) Emission Category but no emissions were reported in that category?

AC:

• Add a new validation function to check this scenario
• Add a corresponding entry in data/prod/application_validation_function.sql
• pgTap test for the new validation function

[hannavovk]

Following up on our conversation: checked with Unit Head - YES, a reverse validation as described in this scenario would be beneficial.
cc: @matthieu-foucault, @dleard, @pbastia