Look into Mapbox GL JS integration via plugin mechanism

[daniel-j-h]

Mapbox GL JS has a plugin mechanism. We should investigate if it makes sense to create such a plugin and then 1/ use it ourselves and 2/ eventually open source it.

Documentaiton

• https://docs.mapbox.com/mapbox-gl-js/plugins/
• https://github.com/mapbox/mapbox-gl-geocoder

cc @ijosc