Issue #3424537: Pluggable Tile Layer Support

js/MapFeature/ControlTileLayers.js

js/MapProvider/GeolocationMapBase.js

js/geolocation-map.js

js/geolocation-shared.js

modules/geolocation_baidu/js/MapProvider/Baidu.js

...cation_baidu/src/Plugin/geolocation/MapProvider/Baidu.php

modules/geolocation_bing/js/MapProvider/Bing.js

modules/geolocation_google_maps/js/MapProvider/GoogleMaps.js

modules/geolocation_leaflet/js/MapProvider/Leaflet.js

package.json

src/Plugin/geolocation/MapFeature/ControlTileLayers.php

src/Plugin/geolocation/TileLayerProvider/Thunderforest.php

src/TileLayerProviderBase.php

src/TileLayerProviderManager.php