#33543 Videos are not stopped when submitting comment

What does this MR do?

This MR does solve this issue #33543 (closed)

• It introduces a new watcher on the field component, when it’s triggered it parses through the usergenerated markup and stops video and audio elements from playing

Issues:

• This is kind of tricky to test since we have to interact with the component to trigger the watcher (eg. updated Props). The existing tests are running against an instance of the component, I couldn’t find a way to updateProps on an instance of a component. Any idea how to update props on the instance of a component? Otherwise the code running in for each needs to be refactored.
• We need some mock-data to run this test, there are plenty of ways where the mock-video could be placed and hosted for karma to find it, any solution you prefer? It is currently embedded from a third party, which needs to be changed.

@winh @donaldcook

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team