FileDatabase Improvements

- small bugfixes
 - Startup configuration to load an arbitrary file database for the API

DeepDrftContent/Models/FileDatabaseSettings.cs

@@ -0,0 +1,7 @@
+namespace DeepDrftContent.Models
+{
+    public class FileDatabaseSettings
+    {
+        public required string VaultPath { get; set; }
+    }
+}