Course import does not save VideoBlock Asides

[asadali145]

When a course XML containing video blocks with Asides is imported into CMS, the Asides state is not retained.

Steps to Reproduce

• Create an Aside that applies to video blocks. Alternatively, you can use ol_openedx_chat
• Now, change the Aside fields of a Video block in CMS.
• Export the course
• Import it in another course in CMS.
• You will notice that it does not retain the Aside state from the exported course.
• You won't face this with the problem blocks.

Reason:

parse_xml parses the Asides from XML blocks. It is called for all other blocks except Videos. Videos have overridden parse_xml and it does not load asides from the XML blocks.

[asadali145]

Closing as fixed #36500