Enrich the copied solr records with coordinate metadata

[dbrower]

This adds some basic enrichment to the metadata records copied from the base vecnet system. It is not perfect, in particular the following still need to be addressed:

• how do we handle items with more than one location. This code builds up a bounding box around everything, but sometimes the bounding box is really small. It is better to use pins in this case.
• It looks like geoblacklight deprecated the solr_bbox field. (see geoblacklight/geoblacklight-schema) Yet we are still relying on it. I tried generating the data without solr_bbox and the bounding boxes did not display.
• The enriched data does not contain links back to the base locations because I don't know which solr field to put the links in.

[dbrower]

One more thing: bounding boxes which cross the anti-meridian do not show up correctly. Solr requires east and west values to be in the range -180 to 180. So, these straddling bboxes have an east coordinate "to the left" their west coordinate. I don't know if it is solr or leaflet which then decides this is an error, and swaps the east and west values, giving a bounding box covering the exact longitudes which the original bbox did not cover.

Could someone please track this down? In fact, I will make an issue for this right now. (Edit: #12)

[stevenvandervalk]

Thanks. Not sure how to address the solr_bbox issue yet. Will look into the meridian.