Deprecate browse indexes in favor of Discovery

[alanorth]

Instead of old "Browse by" searches:

https://cgspace.cgiar.org/browse?type=ilrisubject

We should probably be using Discovery searches:

https://cgspace.cgiar.org/search-filter?field=ilrisubject

Is there anything "Browse by" can do that Discovery can't? Technically they are both using the same SOLR (discovery) backend.

[alanorth]

Blocker for this: Atmire Listings and Reports module requires lucene indexes (for now, at least as of DSpace 4.2).

[alanorth]

Update to above comment: Atmire's Listing and Reports module seems to only require the Lucene search indexes (not browse). This at least makes it half as dependent on Lucene in reality...

[alanorth]

Clarification: after a discussion on the dspace-tech mailing list it seems "Browse by" does in fact use Discovery, so the reason to deprecate it is only for aesthetics (long sidebar #64) and usability (lack of pagination options).

Atmire's Listings and Reports still uses Lucene though, so we need to have them plan an upgrade.

[alanorth]

Update: As of DSpace 5, Atmire has released a new Listings and Reports module that doesn't rely on Lucene. The "Browse by" functionality doesn't use Lucene anyways, so we only need to evaluate whether Discovery works well enough for our use cases...