Type error in AV page metadata

[rhenshaw56]

Is your feature request related to a problem? Please describe.

Currently when validating page level schema.org metadata the AV part shows as an Unspecified Type, as seen on the screenshot below

This needs to be corrected to show a valid type.

Describe the solution you'd like

• Explore alternatives to the solutions considered below
• Validate page-level metadata using this tool

Describe alternatives you've considered

• Adding type of MediaObject to the av metadata - https://schema.org/MediaObject
• Incorporating the AV metadata into the LinkedData component. Doing this also addresses the issue of linking an AV content to it's associated article, listing the video/audio directly under the Article type.

A clear and concise description of any alternative solutions or features you've considered.

Testing notes [Tester to complete]

Dev insight: Will Cypress tests be required or are unit tests sufficient? Will there be any potential regression? etc

• [ ] This feature is expected to need manual testing.

Additional context An example of the expected validation for an article page with multiple videos

[lizcameron]

Closed via #4664