Field Caption Translation - field with the same name in different document type uses the same caption

Tested with CMS v2.26.14 and Repository v2.26.11: translating field captions with the same name in different doc type leads to the same caption.

How to reproduce:
1. In an archetype project, follow the steps in [1] for document type "contentdocument" and "newsdocument"
2. In the [newsdocument/editor:templates/_default_/translator/hippostd:translations/title/hippo:translation], change the "hippo:message" for EN translation to "News Title"
3. In the [contentdocument/editor:templates/_default_/translator/hippostd:translations/title/hippo:translation], change the "hippo:message" for EN translation to "Content Title"
4. Go to CMS and edit a "content" document

Expected: Field "Title" caption is "Content Title"

Current behavior: Field "Title" caption is "News Title"

[1] Internationalization of field captions - http://www.onehippo.org/library/concepts/editor-interface/add-internationalization-i18n-to-document-types.html