Update ReactiveCache call sites to use async/await for Meteor 3.0

Part 3 of ReactiveCache async migration:
- Add await before all ReactiveCache.getX() calls
- Make functions containing ReactiveCache calls async
- Convert forEach/map/filter loops with async callbacks to for...of
- Update model helpers, Meteor methods, JsonRoutes handlers
- Update collection hooks (.before/.after insert/update/remove)
- Update .allow() callbacks to async

Files updated across models/ and server/ directories:
- Model files: cards, boards, lists, swimlanes, activities, users,
  checklists, checklistItems, customFields, attachments, integrations,
  cardComments, settings files, creators, exporters, and more
- Server files: publications, methods, notifications, routes, migrations

models/wekanmapper.js

@@ -1,13 +1,13 @@
 import { ReactiveCache } from '/imports/reactiveCache';
 
-export function getMembersToMap(data) {
+export async function getMembersToMap(data) {
   // we will work on the list itself (an ordered array of objects) when a
   // mapping is done, we add a 'wekan' field to the object representing the
   // imported member
   const membersToMap = data.members;
   const users = data.users;
   // auto-map based on username
-  membersToMap.forEach(importedMember => {
+  for (const importedMember of membersToMap) {
     importedMember.id = importedMember.userId;
     delete importedMember.userId;
     const user = users.filter(user => {
@@ -17,10 +17,10 @@ export function getMembersToMap(data) {
       importedMember.fullName = user.profile.fullname;
     }
     importedMember.username = user.username;
-    const wekanUser = ReactiveCache.getUser({ username: importedMember.username });
+    const wekanUser = await ReactiveCache.getUser({ username: importedMember.username });
     if (wekanUser) {
       importedMember.wekanId = wekanUser._id;
     }
-  });
+  }
   return membersToMap;
 }