The Serials, Mark For, and Other Actions dropdowns in the staff catalog can't be navigated by keyboard

[Jane Sandberg]

Steps to reproduce:
1) In the web staff client, open a bib record.
2) Use the tab key to give focus to the Serials, Mark For, or Other Actions dropdown
3) Press the enter key to open up the dropdown.
4) Try to navigate the dropdown with tab, the arrow keys, or any other keys you can think of. Unfortunately, they do not work.

This is because entries in that dropdown menu are <a> tags with no href attributes, which are not included in the tabindex. I think there are a few different ways we can address this:

1) Add a tabindex="0" attribute to the entries in the dropdown, which would make it navigable by tab.
2) Add a href="#" attribute to the entries in the dropdown, which would make them navigable by tab. This is what the official uib-dropdown examples do.
3) Changing the <a> tags to <button> tags, which would make them navigable by tab
4) Add a keyboard-nav attribute to the div.btn-group (see https://angular-ui.github.io/bootstrap#uib-dropdown-settings), which would make it navigable by arrow keys. I would assume that we probably don't want to do this unless we consistently make all dropdowns in the UI navigable by arrow keys.

[Kate Coleman (katecoleman)]

Confirmed in webclient 3.1.10 using steps above. Can tab through the main menu fine, but when getting to a dropdown menu, cannot navigate any further via keyboard.

[Josh Stompro (u-launchpad-stompro-org)]

Related bug #1697003 (webstaff: keyboard-nav for uib-dropdown)

[Erica Rohlfs (erohlfs)]

There might be a slight change in version 3.7. I can follow steps 1 - 3. When I get to step 4, I can use the tab key to select either "Manage Subscriptions" or "Manage MFHD." However, the arrow keys still do not allow for navigation.

[Stephanie Leary (stephanieleary)]

These submenu items just need the ngbDropdownItem directive to add keyboard support.

Branch here:
https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/sleary/LP1814978-bib-action-dropdown-kbd

[Susan Morrison (smorrison425)]

Confirmed ability to navigate using the arrow keys within the Serials, Mark For, or Other Actions dropdown menus.

I have tested this code and consent to signing off on it with my name, Susan Morrison, and my email address, <email address hidden>.

[Jane Sandberg (sandbergja)]

Thanks, Stephanie and Susan! Added to rel_3_10 and above.