Implement limiting caches (#13605)

* Implement basic expiring cache for LibraryManager

* Add expiring cache to more places

* Rider why

* Make DirectoryService caches static

* Use FastConcurrentLru

* Reduce default cache size

* Simplify DirectoryService caches

* Make directory service cache size at least 128

MediaBrowser.Model/Configuration/ServerConfiguration.cs

@@ -177,6 +177,11 @@ public class ServerConfiguration : BaseApplicationConfiguration
     /// <value>The library update duration.</value>
     public int LibraryUpdateDuration { get; set; } = 30;
 
+    /// <summary>
+    /// Gets or sets the maximum amount of items to cache.
+    /// </summary>
+    public int CacheSize { get; set; } = Environment.ProcessorCount * 100;
+
     /// <summary>
     /// Gets or sets the image saving convention.
     /// </summary>