Refactor media action with getAllLinked

[mcbouslog]

Staging branch URL: https://pr-5591.pfe-preview.zooniverse.org

Fixes lab/media page size issue, as noted in this Talk post.

Refactors media fetch action to use getAllLinked helper.

Comparing https://www.zooniverse.org/lab/5483/media to https://pr-5591.pfe-preview.zooniverse.org/lab/5483/media?env=production, searching for "https://panoptes-uploads", returns 200 results on master as expected compared to 427(!) on this staged branch.

Required Manual Testing

• Does the non-logged in home page render correctly?
• Does the logged in home page render correctly?
• Does the projects page render correctly?
• Can you load project home pages?
• Can you load the classification page?
• Can you submit a classification?
• Does talk load correctly?
• Can you post a talk comment?

Review Checklist

• Does it work in all major browsers: Firefox, Chrome, Edge, Safari?
• Does it work on mobile?
• Can you rm -rf node_modules/ && npm install and app works as expected?
• If the component is in coffeescript, is it converted to ES6? Is it free of eslint errors? Is the conversion its own commit?
• Are the tests passing locally and on Travis?

Optional

• Have you replaced any ChangeListener or PromiseRenderer components with code that updates component state?
• If changes are made to the classifier, does the dev classifier still work?
• Have you resized and compressed any image you've added?
• Have you added in flow type annotations?
• Have you followed the Springer guidelines for commit messages?

[coveralls]

Coverage increased (+0.003%) to 49.354% when pulling dcf00cf on media-fetch-page-size into 2d81e61 on master.

[wgranger]

Nice. Good use of the lib function we already have. Are we at all concerned about providing limitless amounts of media uploads?

[mcbouslog]

Closing in favor of paginator.