-implement the up/down keys for the gallery view/slide modal

[dstopp]

• Fixes #715
• Were any Django, import pipeline, table_schema, or dictionary files modified? Y/N
  • If YES:
  • Database used: opus3_test_200903
  • All Django tests pass: NA
  • FLAKE8 run on modified code: NA
• Were any JavaScript or CSS files modified? Y
  • If YES:
  • JSHINT run on all affected files: Y
  • Tested on Chrome, Firefox, Safari, Edge, and iOS: Y/NA (Remember to test all browser sizes)
  • Tested for race conditions (with delayed API calls if applicable): NA

Description of changes: -Catch the up and down arrows when the modal is open; in gallery view, the up/down will move the binoculars up or down one row and update the modal w/the new opusID; in table view, the up/down will do the same as next/prev and move one up or one down, then update the modal. -if there are no more rows up or down, the up/down arrow will do nothing.

Known problems:

• there is a bug in the table view that causes the highlighted row to always be at the bottom of the screen once it reaches a certain part of the visible screen.
• there is a bug for a corner case when the binoculars or highlighted row are scrolled up off the screen, edit of the metadata fields will cause the metadata on the slide view modal to disappear

[juzen2003]

• There are two issues:
  1. Binoculars stay on the gallery view after some changes in select metadata menu.
     • Steps to reproduce the issue:
       1. Start OPUS freshly, and go to gallery view.
       2. Click on any thumbnail to open the metadata modal, and then close it.
       3. Go to select metadata menu and add something like volume id, and then save.
       4. Binoculars will stick to the thumbnail we clicked at step b with metadata modal closed. Hitting left/right arrows won't do anything and up/down arrows will move the scrollbar without moving the binoculars. Need to click on any thumbnail again to open the metadata modal and resume the correct behavior of binoculars.

2. In console, error message: metadataboxHtml: in each, observationData may be out of sync with colLabels;
   • Steps to reproduce the issue:
     1. Add some API delay.
     2. In gallery view, open up a metadata detail modal, and hold the down arrow key and it will move down to trigger initInfiniteScroll load.
     3. When spinner is still running, click edit in the modal and delete a metadata col. At the same time, keeping hitting down key maybe for about 3 to 4 times, then we can see the error message in the console. Most of the time, all metadata info will still be loaded fine, but sometimes it will have a blank right pane without any metadata info.

[dstopp]

re: 1. Binoculars stay on the gallery view after some changes in select metadata menu - that has been resolved.

re: 2. In console, error message: metadataboxHtml: in each, observationData may be out of sync with colLabels; This issue is in production code and is an unrelated bug. It is easy to dup in production code w/out any delays by using the table view, edit metadata, etc, similar as described above.