Add additional channels to the Android TV Launcher

[colino17]

This is in response to the following issue.

This pull request relates to how the app integrates with the Android TV / Google TV Launcher. It does not change the appearance or functionality inside the Dune application itself.

Currently the application offers a handful of "channels" which can be used in the Google TV launcher or in third party launchers like Projectivy to provide recommendations. These include "next up", "latest movies", "latest episodes", and "all libraries" options. The "all libraries" option shows links to each library (ex: movies, shows, cartoons) but does not show the content of each library itself.

This pull request does the following:

• Adds new launcher channels for all movies, all series, and all movie collections which allows quick access to Jellyfin content directly from the Android TV / Google TV Launcher.
• Adds a toggle under the enhanced setting menu that adds a preference for thumbnails over posters for content displayed on the Android TV / Google TV Launcher. Note that this does not affect image preferences within the app itself. It only changes whether the launcher uses posters or thumbnails by default.

Notes

• I added a string for the image toggle setting to the strings.xml file, however I'm not sure exactly how the translation pipeline works so I did not update any of the localized strings.
• The default Google TV launcher does not add much customization and still seems to prioritize paid content over Jellyfin content so I'm not sure how readily any of this information will be displayed by Google. However, third party launchers such as Projectivy allow selection of only the channels you want and seems to work wonderfully with these additional channels (aside from a bit of a delay initially caching images if you have large libraries). Using the additional channels with these launchers is completely optional so it should not affect users who do not need this functionality.

[Sam42a]

I was always gonna add some more channels/customization to the android TV channels, but never got to it.
This is great! thanks for the pr.