d2571e10d6
Supports `hasMany` upload fields, similar to how `hasMany` works in
other fields, i.e.:
```ts
{
type: 'upload',
relationTo: 'media',
hasMany: true
}
```
---------
Co-authored-by: Jacob Fletcher <jacobsfletch@gmail.com>
Co-authored-by: James <james@trbl.design>