test: reliability fixes to testsortAzul (#4210)

[jpaten]

Ticket

Closes #4210.

Reviewers

@MillenniumFalconMechanic .

Changes

• Altered AnVIL-CMG sort tests as follows
  1. Load the specified tab
  2. Check that the first column starts with the "sort icon" visible
  3. Click the first column sort button
  4. Check that the sort icon is still visible
  5. For all other default columns:
  6. Check that the sort icon is not visible
  7. Click the sort button
  8. Check that the first cell in that column is visible (just to check nothing's broken, it doesn't need to have text)
  9. Check that the sort icon for the previous column is not visible
  10. Check that the sort icon for the current column is visible

Known Issues

• Uses a toHaveCSS assertion to check whether cells are visible, since currently test icons just have opacity set to 0 when not visible, which Playwright doesn't check. Could avoid this with a test id or other attribute if desired

[MillenniumFalconMechanic]

LGTM, thanks Jonah!