add code to update youtube data for videos

## Problem
A video is created in the backend whenever someone attempts to add segments to a video that is not found in the db. The video that is created contains the metadata for the youtube video, such as the description. However after the video is created this youtube metadata is never updated.

## Solution
When we list videos (either the default list or after a search) we should include some logic that checks if the youtube data within the videos is out of date and update them if it is.

The issue names the default video list and search results as entry points, but no files or tests. Start by locating those listing paths and the existing YouTube metadata handling; done means out-of-date metadata is refreshed in both listing modes.

Written by the indexing model from the issue text.