[external map viewer] Add WFS to map: empty ${service.name} variable

[jeanpommier]

Describe the bug
When an external map viewer is configured, the ${service.name} variable is an empty string. Consequently not adding the layer to the map.

I tracked it down to https://github.com/geonetwork/core-geonetwork/blob/main/web-ui/src/main/resources/catalog/components/metadataactions/RelatedResourcesService.js#L150 where the featureName, used just below, is resolved to ''. Is there a reason to try to localize the feature name ? It seems strange. And it is looking for link.title, which doesn't exist in my case. Shouldn't it look for link.name instead ?

To Reproduce
Steps to reproduce the behavior:

1. Configure an external viewer string, for instance /mapstore/#/?actions=[{"type":"CATALOG:ADD_LAYERS_FROM_CATALOGS","layers":["${service.name}"],"sources":[{"type":"${service.type}","url":"${service.url}"}]}]
2. Create a metadata with a WFS related resource
3. Click on the Add to Map link for this resource and look at the generated URL params

Expected behavior
service.name should give the layer name