Add editor scraping for test_cases and test_code

[thebioengineer]

Add editor scraping for test cases and test code (#87), and the consolidate editor scraping functions into the same RD file.

Renaming functions to be more explicit:

• vtscrape -> vtscrape_editors

Also identified naming collision with vt_kable_test_code so:

• vt_kable_test_code -> vt_kable_test_code_results (kable's the test code results, not the editors)
• vtkable -> vtkable_editors

[thebioengineer]

Need to have #110 completed first and update this PR accordingly.