Describe the bug
When you have a page with a piece of content that have a Key/Value field the response of that field is an string of an object instead of the objet itself

To Reproduce
Steps to reproduce the behavior:

1. Go to https://starter.dotcms.com:8443/api/v1/page/render/store/products/tecnica-jt-3-pearl-girls-ski-boots-2020
2. Search for the specifications1 field
3. See the response there

Expected behavior
It should be an object so in the FE we don't have to parse it

Acceptance Criteria

1. Fix the response accordingly
2. Work in all the supported browsers (don't forget IE11 and iPad)
3. Multilanguage
4. Unit test