Move In Progress ostrio-files changes to separate branch, and revert ostrio-files changes, so that:

- Export to CSV/TSV with custom fields works
- Attachments are not exported to disk
- It is possible to build arm64/s390x versions again.

Thanks to xet7 !

Related #3110

models/cards.js

@@ -412,14 +412,10 @@ Cards.helpers({
     const _id = Cards.insert(this);
 
     // Copy attachments
-    oldCard.attachments().forEach((file) => {
-      Meteor.call('cloneAttachment', file, 
-        {
-          meta: {
-            cardId: _id
-          }
-        }
-      );
+    oldCard.attachments().forEach(att => {
+      att.cardId = _id;
+      delete att._id;
+      return Attachments.insert(att);
     });
 
     // copy checklists
@@ -522,15 +518,14 @@ Cards.helpers({
   attachments() {
     if (this.isLinkedCard()) {
       return Attachments.find(
-        { 'meta.cardId': this.linkedId },
+        { cardId: this.linkedId },
         { sort: { uploadedAt: -1 } },
       );
     } else {
-      let ret = Attachments.find(
-        { 'meta.cardId': this._id },
+      return Attachments.find(
+        { cardId: this._id },
         { sort: { uploadedAt: -1 } },
       );
-      return ret;
     }
   },
 
@@ -539,7 +534,7 @@ Cards.helpers({
     const cover = Attachments.findOne(this.coverId);
     // if we return a cover before it is fully stored, we will get errors when we try to display it
     // todo XXX we could return a default "upload pending" image in the meantime?
-    return cover && cover.link();
+    return cover && cover.url() && cover;
   },
 
   checklists() {