Horizontal Feed service cursor

Summary

Allow faster pagination when going back and forth on media modal

• Closes #2419 (closed)

Steps to test

• Go to a channel with media content
• Click on a image or a video
• There should be a really small delay for the arrows to appear.
• Try navigating back and forth, there should be no delay for the arrows to pop-in.
• When navigating, check the dates to see if you're going back and forth.
• Go to a group (such as: https://goal-modal-pager-cache.minds.io/groups/profile/1051617384458096641/feed)
• Upload an image with your user
• Navigate through it, other images in that group (uploaded by another users) should appear

Known issues

There's an engine issue, which affects the entity displayed on the modal. engine#1326

Estimated Regression Scope

Regressions might arise when loading the media modal or navigating on it.