Replace remove the need for calling `getValue()` methods on model objects

It looks like the API leaks the `.value` JSON element into the API, which means the developer needs to call `.getValue()` in a few different places.

Ideally this should be handled when the JSON is parsed, so a developer can call something like:

```java
userProfileFormValue.form()
```

instead of:

```java
userProfileFormValue.form().getValue();
```