Make gamelab and spritelab animation libraries use the same category previews again

[JillianK]

In this PR I added logic and pngs so that gamelab and spritelab could use different category previews since we were updating the gamelab animation library with new categories. Now, we're updating the spritelab animation library with new categories so we need to take that logic out.

This also includes a change to change the display name for the "Game Blocks" category to "Video Games".

And the change in constants.rb is for the animation library manifest builder script

Links

• original PR to add the preview distinction
• jira

Testing story

Reviewer Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked

[maddiedierker]

🎉 yay, we're getting closer to a new animation library!