Group URL links

When the user navigates to a URL by double-clicking on a sequence id, or via the Links menu, Jalview constructs a URL from the sequence id or associated DB accession ids. In some cases it makes sense to link to a URL determined by multiple database accession ids. For example, a sequence may have multiple associated Gene Ontology accession ids, and we would like to construct a link from these which incorporates them all, so that if the GO terms are GO:0005737 and GO:00046872, a possible corresponding link is
http://amigo.geneontology.org/amigo/search/bioentity?q=GO:0009507%20GO:0005737

Ideally the information about which databases can be accessed in this way, and the corresponding link format, should be downloaded from an online resource. This resource remains to be identified. It may be possible to set this up using the Elixir tools & resources registry (discussions ongoing).

Relates to JAL-2316 which added identifiers.org urls to the set of links available to the user. Issues raised in JAL-402 may also apply.