Remove bottom margin from the media player

[chris-hinds]

Is your feature request related to a problem? Please describe.
The psammead media player currently has some bottom margin set. This pushes down the video captions when they are rendered as the captions are rendered outside of the media player container.

Describe the solution you'd like
Remove the bottom margin from the psammead-media-player component.

Where custom styling is required add this to the component in simorgh, psammead-media-player is a generic component used across multiple page types and some page types require different styling, this custom styling should live within simorgh and not the media player component.

Bump package with a major version and don't automatically integrate with Simorgh. Do this via the follow-up issue: bbc/simorgh#7692

Describe alternatives you've considered
N/A

Testing notes

• Ensure snapshots are up to date

Dev insight: Will there be any potential regression? etc

• This feature is expected to need manual testing.

Additional context
Add any other context or screenshots about the feature request here.