More cleanup and making some constants

Models/CoverArt.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations.Schema;
 using System.Linq;
+using System.Reflection.Metadata;
 using System.Text;
 
 using Newtonsoft.Json;
@@ -23,12 +24,12 @@ public class CoverArt
     #region Methods
     public string GenerateFilename(int flag)
     {
-        const int length = 25;
-        const string chars = "ABCDEF0123456789";
+        int length = Constants.DirectoryPaths.FILENAME_LENGTH;
+        string chars = Constants.DirectoryPaths.FILENAME_CHARACTERS;
         var random = new Random();
         var filename = new string(Enumerable.Repeat(chars, length).Select(s =>
             s[random.Next(s.Length)]).ToArray());
-        var extension = Icarus.Constants.FileExtensions.JPG_EXTENSION;
+        var extension = Constants.FileExtensions.JPG_EXTENSION;
 
         return (flag == 0) ? filename : $"{filename}{extension}";
     }