CacheBox Pre-Release

Added significant changes to file system including thumbnails using jellyfin posters fallbacking to video_thumbnail for video and ClipRRect for images with caching listview for faster thumbnail retrieval once built. improved file storage with more robust file parsing and file functions such as details and rename. added folders directory traversal. added subtitle and audio track controls as well as replay controls with autoplay canceling resume marker for next video in playlist, replay all works with all video and audio files within the current folder. moved upload button to group home appbar instead of floating action button on file screen and is still only visible while file screen is visible.