BUGFIX: Resolve console errors while jests test

[markusguenther]

When we run our jest test we have plenty of console.errors in the output. That is distracting and should not happen.

We want to prevent errors like Warning: Failed prop type: The prop editorRegistryis marked as required inEditorEnvelope, but its value is null.

What I did Walked through all packages and searched which packages were effected.

• [x] neos-ui
• [ ] neos-ui-editors
• [ ] neos-ui-sagas

[markusguenther]

Will go thru all errors and hopefully resolve them.

[markusguenther]

About the sagas, I am unsure if this can be removed ... there we test error handling.