Restore and fix basemap-kartverket

[dstien]

Restore the deleted plugin for layers from the Norwegian Mapping Authority's cached GMaps compatible tile service.

This includes the fix #1288 by gusowski1 tracked in #2, and supersedes the changes in the mentioned #1006 by sollie.

Included an additional nautical chart layer, useful for checking access to coastal portals.

[johnd0e]

I want to add some background.

• Kartverket maps on the web: https://www.norgeskart.no/
• Official Set up the page in the Leaflet
• Sample plugin: https://github.com/kartverket/example-clients/blob/master/leaflet/js/L.TileLayer.Kartverket.min.js
• (More updated) plugin listed on leaflet page: https://github.com/knreise/L.TileLayer.Kartverket

So yes, Kartverket map will be added, but the PR should be improved.

[johnd0e]

See #133