Description

When editing a ZString object which type is not unbound (it could be any other type), the ZObjectType can be expanded, but it doesn't show any key-values.
This is probably to the way terminal objects are handled in the store, and how it behaves when trying to convert a terminal ZObject into a non-terminal one (e.g. changing a ZString and instead having a ZMonolingual string)

Steps to reproduce:

1. Go to https://wikifunctions.beta.wmflabs.org/w/index.php?title=Z10112&view=default-view&action=edit
2. Expand one of the values of the list under "Common names"

Observed behavior:

• The key "Type" has an expansion toggle even if it cannot be edited
  
• When expanding the key "Type", the key-value-set below is empty
  

Another example to replicate this locally

1. Create a new ZObject locally of type String (by going to http://localhost:8080/wiki/Special:CreateZObject?zid=Z6, set a value for the object and save it)
2. Go to the saved ZObject page in Default and Edit modes (by setting the url to ?view=default-view&action=edit)
3. Expand the key "Value" and the key "Type"

Expected behavior (Acceptance criteria):

• For non editable types, the toggle should not be present
• For editable types, the toggle should appear but when expanding, the key-values (type: Reference, value: String) should be visible

Devices and Design (URLs or screenshots, if applicable):

• Desktop: ...
• Small screens/mobile: ...

Completion checklist

• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Front-end_Task/Bug_Completion_Checklist