wip: remove Leaflet.i18n from frontend and expose L._

But we keep Leaflet.i18n for now, as we use its script to collect
strings (this script to be tweaked to support also `translate`).

umap/static/umap/js/modules/i18n.js

@@ -1,7 +1,7 @@
 // Comes from https://github.com/Leaflet/Leaflet/pull/9281
 import { Util } from '../../vendors/leaflet/leaflet-src.esm.js'
 
-const locales = {}
+export const locales = {}
 
 // @property locale: String
 // The current locale code, that will be used when translating strings.
@@ -19,7 +19,7 @@ export function setLocale(code) {
 }
 // @function translate(string: String, data?: Object): String
 // Actually try to translate the `string`, with optionnal variable passed in `data`.
-export function translate(string, data) {
+export function translate(string, data = {}) {
   if (locale && locales[locale] && locales[locale][string] !== undefined) {
     string = locales[locale][string]
   }

umap/static/umap/js/modules/leaflet-configure.js

@@ -4,3 +4,4 @@ import * as L from '../../vendors/leaflet/leaflet-src.esm.js'
 import * as i18n from './i18n.js'
 
 window.L = { ...L, ...i18n }
+window.L._ = i18n.translate

umap/static/umap/test/index.html

@@ -8,7 +8,6 @@
     <script src="../vendors/editable/Path.Drag.js" defer></script>
     <script src="../vendors/editable/Leaflet.Editable.js" defer></script>
     <script src="../vendors/hash/leaflet-hash.js" defer></script>
-    <script src="../vendors/i18n/Leaflet.i18n.js" defer></script>
     <script src="../vendors/editinosm/Leaflet.EditInOSM.js" defer></script>
     <script src="../vendors/minimap/Control.MiniMap.min.js" defer></script>
     <script src="../vendors/csv2geojson/csv2geojson.js" defer></script>

umap/templates/umap/js.html

@@ -12,7 +12,6 @@
 <script src="{% static 'umap/vendors/editable/Path.Drag.js' %}" defer></script>
 <script src="{% static 'umap/vendors/editable/Leaflet.Editable.js' %}" defer></script>
 <script src="{% static 'umap/vendors/hash/leaflet-hash.js' %}" defer></script>
-<script src="{% static 'umap/vendors/i18n/Leaflet.i18n.js' %}" defer></script>
 <script src="{% static 'umap/vendors/editinosm/Leaflet.EditInOSM.js' %}"
         defer></script>
 <script src="{% static 'umap/vendors/minimap/Control.MiniMap.min.js' %}"