feat(web): bundle and 'sveltify' leaflet (#1998)

* feat(web): bundle and 'sveltify' leaflet

* lazy load leaflet components

* add correct icon sizes

web/src/lib/utils/context.ts

@@ -0,0 +1,8 @@
+import { getContext, setContext } from 'svelte';
+
+export function createContext<T>(key: string | symbol = Symbol()) {
+	return {
+		get: () => getContext<T>(key),
+		set: (context: T) => setContext<T>(key, context)
+	};
+}