Geoplatform reference link

## User Story

In order to collaborate with Geoplatform and keep map/spatial tools to a minimum on data.gov, Geoplatform and data.gov wants the link between services turned back on.

## Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using [BDD](https://en.wikipedia.org/wiki/Behavior-driven_development#Behavioral_specifications).]

- [ ] GIVEN the necessary development is complete \
WHEN a user accesses a dataset page that is geospatial (such as https://catalog.data.gov/dataset/2015-16-harassment-or-bullying-estimations-by-basis-category) \
THEN the link to the same record on geoplatform is displayed

## Background

We did this before on the CKAN catalog. The Geoplatform API call to get the Geoplatform equivalent URL from our dataset slug is `https://geoplatform.gov/prod/v3/public/lookups/data-gov/dataset?name=`, and simply attach the slug at the end.
Example: https://geoplatform.gov/prod/v3/public/lookups/data-gov/dataset?name=2015-16-harassment-or-bullying-estimations-by-basis-category
Response should contain a JSON object with the key `geoplatform_url`, which is what we should display/link to.

CKAN code: https://github.com/GSA/ckanext-datagovtheme/blob/main/ckanext/datagovtheme/fanstatic_library/scripts/geoplatform.js

Please note the URL may have changed from previous version, but URL above works as of 5/14/2026.

## Security Considerations ([required](https://nvd.nist.gov/800-53/Rev4/control/CM-4))

[comment]: # "Our SSP says 'The Data.gov team ensures security implications are considered as part of the agile requirements refinement process by including a section in the issue template used as a basis for new work.' so please don't remove this section without care."
None

## Sketch

Do a client-side check to see if the information should be displayed (any cached data/information may be liable to be out of date). If it works and you get information, display the link somewhere on the UI. Suggest near the map location information, as that will be where the spatial people are drawn, like moths to a flame.