Remember which categories are expanded (fixes 720,785,938)

[rfrenchseti]

• Fixes #720, #785, #938
• Were any Django, import pipeline, table_schema, or dictionary files modified? Y
  • Database used: opus3_test_200107
  • All Django tests pass: Y
• Were any JavaScript or CSS files modified? Y
  • JSHINT run on all affected files: Y
  • Tested on Chrome, Firefox, Safari, and iOS: Y (Remember to test all browser sizes)
  • Tested for race conditions (with delayed API calls if applicable): Y

Description of changes:

Change how expanded categories are remembered when a new search menu (left side of Search tab) or a new Select Metadata menu (left side of Select Metadata dialog) is fetched due to a change in the search constraints. Now the list of expanded categories is passed to the Django, which includes the appropriate collapsed/show classes in the returned HTML. This eliminates the previous kludge of having the JS expand the categories after the HTML is loaded, resulting in a flicker.

Known problems:

None

[juzen2003]

• Database used: opus3_test_200107
• All Django tests pass: Y
• JSHINT run on all affected files: Y (widgets.js & selectMetadata.js)
• Tested on Chrome, Firefox, Safari, and iOS: Y (Remember to test all browser sizes)
• Tested for race conditions (with delayed API calls if applicable): Y