Feature/issue 194

[nlenssen2013]

Github Issue: #194

Description

Variables requested in coordinate variables, that aren't a dimension to another variable are not included in output

Overview of work done

Change the variable subsetting in bbox to loop through all variables rather than just data variables

Overview of verification done

Test that the variable 'PRODUCT/corner' in S5P CH4 subset is returned when it is requested

Overview of integration done

Explain how this change was integration tested. Provide screenshots or logs if appropriate. An example of this would be a local Harmony deployment.

PR checklist:

• [ x] Linted
• [ x] Updated unit tests
• Updated changelog
• Integration testing

See Pull Request Review Checklist for pointers on reviewing this pull request

[danielfromearth]

@nlenssen2013, this looks good. I just made a few tweaks for readability & typing. The code's logic here is getting quite dense, so i'm just hoping to keep it as readable and manageable as possible.