Extracted WordCloud XBlock won't edit in a Content Library V2 #123

Description

The XBlocks can be created, edited in a Content Library V2. Unlike the BuiltIn WordCloud, the extracted one can't be edited in a Content Library V2.

Steps to Reproduce

1. Make sure the extracted WordCloud XBlock is enabled in the edx-platform settings (USE_EXTRACTED_WORD_CLOUD_BLOCK = True)
2. Go to a Content Library.
3. Click "New" to add a new Component.
4. In the right pane, click "Advanced/Other" and select "Word cloud" from the list
5. WordCloud will be created
6. Click the three dots Menu ⋮ and click Edit.
7. Make some changes in the WordCloud configuration and hit "Save"
8. You will see the error message "An unexpected error occurred in the editor"

Acceptance Criteria:

• WordCloud XBlock can be created in a Content Library V2 library, edited, published
• WordCloud Xlock from a library can be used in a course, and its text can be overridden