Play local trailers

[1hitsong]

Changes
Adds support for playing local trailers to the movie detail page.

Demo
See it in action: https://twitter.com/1hitsong/status/1563694392329781248

Fixes: #350

[neilsb]

Seems to work well. Only difference from web is that it will play all the trailers once after the other (if there are multiple), whereas this will only play the 1st one in the list returned by the API with no ability to see any of the others.

Not saying that is not a valid thing to do - just querying if it was intentional?

[1hitsong]

It was intentional this time.

We don't have an API param for StartItemId like we do with PlayNextEpisode. So we would need to keep track of which one just played and which is next, etc. I figured instead of adding all that code immediately, we'd take the first baby step in supporting local trailers.

Once the video manager / playlist work is completed, then we can add all the trailers as a playlist and this won't be an issue.

When/if this is released, we should note this difference from the WebUI.

[jimdogx]

FYI, this Fixes: #350