Add LocationIQ as supported map provider (#1293)

- Add LocationIQ access token field to settings and export modals
  - Include LocationIQ Streets style in gallery
  - Support automatic token replacement for LocationIQ URLs
  - Add LocationIQ tileset configuration
  - Include translations for all supported languages

## Launch Checklist
 - [x] Briefly describe the changes in this PR.
 - [x] Write tests for all new functionality.
 - [x] Add an entry to `CHANGELOG.md` under the `## main` section.

src/config/tilesets.json

@@ -18,5 +18,10 @@
     "type": "vector",
     "url": "https://s3-eu-west-1.amazonaws.com/tiles.os.uk/v2/data/vector/open-zoomstack/config.json",
     "title": "OS Open Zoomstack v2"
+  },
+  "locationiq": {
+    "type": "vector",
+    "url": "https://tiles.locationiq.com/v3/pbf/tiles.json?key={key}",
+    "title": "LocationIQ"
   }
 }