IE11 doesn't support responseType: json

Steps to reproduce the behavior

1. Using IE (even IE11), access the admin panel. Any website is fine, even the demo website. You might need fix #3733 to do that.
2. Select a model to list all its entries

Expected behavior

See the entries

Actual behavior

The entries aren't shown and the loader stays where it is. The error occurs in the method showBlankState(). The reason is that the value of this.props.items is a string and not an array. Therefore, IE isn't able to access the property results and this code this.props.items.results.length generates an error.