When selecting multiple regions the resulting video list should be truncated

[matthieugrieger]

Currently, when multiple regions are selected a larger number of videos are displayed on the playlist page than if you use just one region. The number of videos should be restricted (likely to the value of the number of results filter).

[matthieugrieger]

Also, when the list is truncated the order filter should be taken into account (if it was set to something).

For example, if the user wanted the videos sorted by date we should make sure to sort the list of videos by date before truncating it.

[matthieugrieger]

If we decide to truncate the video list to the user's number of videos filter choice, we can also get rid of the code added in this commit: 1d055a6