Function sync

Synchronize the Tagger database with the filesystem. This includes: Checking for new files not yet recorded in the database and adding them Checking for old files which have disappeared from the filesystem and removing them from the database Optionally generating preview artifacts from any new files Optionally comparing new files with each other and existing files to identify duplicates

(
    conn: &AsyncMutex<SqliteConnection>,
    image_locks: &LockMap<Arc<str>, ()>,
    image_dir: &str,
    cache_dir: &str,
    preload: bool,
    deduplicate: bool,
)