Allow bookmarks page to be sorted by library

[sandbergja]

User story

From a libanswers user:

[It would be amazing] to be able to sort bookmarks by library

Acceptance criteria

• The bookmarks page includes an option to sort by library (as well as the existing sort options such as year, author, and title)
• I can successfully use this feature with Voice Over in Safari.
• I have checked this feature using one of the following browser extensions and confirmed that it does not add any level A or level AA issues:
  • axe dev tools
  • Lighthouse
  • Wave

Notes

Related ticket #4305

We were thinking about removing the Relevance option as part of this ticket. However, it is difficult to remove this given current Blacklight configuration options, and it wasn't necessary to address this user's need. So we removed it as a success criteria. It may be useful to do a Blacklight feature request in the future to allow the default option to accept a lambda as if or unless condition (as other config options do).

[sandbergja]

@ellen-aa @caroldh what do you think?

[ellen-aa]

High priority to me - would be great to do at the same time as 4305. @caroldh, what do you think?