CMS Data Model Object Type number key lookup

**Describe the bug**
When creating a CMS Data Model with an object that has numbers as keys the data binding fails.
It tries to access the data with:
```javascript
state.dataModel.object.1
```
In this case it then returns the entire object and not the selected value.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a CMS Data Model.
2. Add an object field with a field that has a number key.
3. Connect the model to your page and bind the object field anywhere.

**Expected behavior**
I expect to be able to use number keys, that are used as a string to lookup the property.

This should work:
```javascript
state.dataModel.object["1"]
```