Download button: take advantage of MVT server, download button will now attempt to download everything

src/UI/DownloadFlow/DownloadButton.svelte

@@ -3,10 +3,8 @@
   import { ArrowDownTrayIcon } from "@babeard/svelte-heroicons/mini"
   import Tr from "../Base/Tr.svelte"
   import Translations from "../i18n/Translations"
-  import type { FeatureCollection } from "geojson"
   import Loading from "../Base/Loading.svelte"
   import { Translation } from "../i18n/Translation"
-  import DownloadHelper from "./DownloadHelper"
   import { Utils } from "../../Utils"
   import type { PriviligedLayerType } from "../../Models/Constants"
   import { UIEventSource } from "../../Logic/UIEventSource"
@@ -16,14 +14,11 @@
   export let extension: string
   export let mimetype: string
   export let construct: (
-    geojsonCleaned: FeatureCollection,
     title: string,
     status?: UIEventSource<string>
-  ) => (Blob | string) | Promise<void>
+  ) => Promise<Blob | string>
   export let mainText: Translation
   export let helperText: Translation
-  export let metaIsIncluded: boolean
-  let downloadHelper: DownloadHelper = new DownloadHelper(state)
 
   const t = Translations.t.general.download
 
@@ -31,30 +26,21 @@
   let isError = false
 
   let status: UIEventSource<string> = new UIEventSource<string>(undefined)
-
   async function clicked() {
     isExporting = true
+    
     const gpsLayer = state.layerState.filteredLayers.get(<PriviligedLayerType>"gps_location")
     state.userRelatedState.preferencesAsTags.data["__showTimeSensitiveIcons"] = "no"
     state.userRelatedState.preferencesAsTags.ping()
     const gpsIsDisplayed = gpsLayer.isDisplayed.data
     try {
       gpsLayer.isDisplayed.setData(false)
-      const geojson: FeatureCollection = downloadHelper.getCleanGeoJson(metaIsIncluded)
       const name = state.layout.id
 
       const title = `MapComplete_${name}_export_${new Date()
         .toISOString()
         .substr(0, 19)}.${extension}`
-      const promise = construct(geojson, title, status)
-      let data: Blob | string
-      if (typeof promise === "string") {
-        data = promise
-      } else if (typeof promise["then"] === "function") {
-        data = await (<Promise<Blob | string>>promise)
-      } else {
-        data = <Blob>promise
-      }
+      const data: Blob | string = await construct(title, status)
       if (!data) {
         return
       }