Avoid error "All objects must exist on the server" on calling fetchAll() #5950
Description
Is your feature request related to a problem? Please describe.
When you need to fetch a list of objects which can be managed (or deleted) by other users, you risk getting an error "All objects must exist on the server" if any of those objects no longer exists.
Describe the solution you'd like
Ideally, the call to ParseObject.fetchAll() could ignore nonexistent objects and go on with the rest of the results.
Describe alternatives you've considered
The current way of avoiding this problem is not using fetchAll() but instead creating a new query:
let objectList = [...someObjects];
objectList = await new Parse.Query('Foo')
.containedIn('objectId', objectList.map(o => o.id))
.find();