Changing the Name and the Predefined value of a Statement in one action causes some errors

[helkv]

Testserver: qa edmond (qa imeji)
Browser: ff
Version: 4.9.3 (version 4.9.4 - build date 2020-07-08 09:46:54 )
User: Admin

Changing the Name together with the Predefined value of a Statement causes problems:

• Items using the Predefined value of the Statement as Metadata are not correctly displayed in the Edit item view any more
  • The Metadata with the Predefined value is missing in the Edit item view
• Saving such an item creates a new Statement with the new Statement Name and Predefined value

Actions:

1. Login as Admin
2. Create Statement
   1. From Type Text
   2. With a Predefined value
3. Add the Predefined value as Metadata to an item
4. Update the Statement:
   1. Change the name of the Statement and the Predefined value in one action
5. Open Edit item view of the edited item
   1. The Predifined value Metadata of the Statement is missing in the Edit item view
   2. Only the 'Remove' button of the Metadata is visible
6. Save the item
7. The old Statement and a new updated Statement is listed in the Browse Statements view

[helkv]

Also see related issue: #1190