add command-line options support

new command-line option "--bank <filename>" can be specified to be used instead of the game config option

App/CommandLineOptions.cs

@@ -1,7 +1,22 @@
 namespace Game {
     public struct CommandLineOptions {
+        public string? databaseFilename = null;
+        public CommandLineOptions() {
+
+        }
         public static CommandLineOptions Parse(string[] args) {
-            return new CommandLineOptions();
+            string? databaseFilename = null;
+            for (int i = 0; i < args.Length; ++i) {
+                string arg = args[i];
+                if (arg.StartsWith("--bank")) {
+                    if (arg.Length > 6 && arg[6] == '=') {
+                        databaseFilename = arg.Substring(7);
+                    } else if (args.Length > i + 1) {
+                        databaseFilename = args[i + 1];
+                    }
+                }
+            }
+            return new CommandLineOptions() { databaseFilename = databaseFilename };
         }
     }
 }

App/Program.cs

@@ -29,7 +29,7 @@ namespace Game {
                 return 2;
             }
 
-            string databaseFileName = gameConfig.databasePath;
+            string databaseFileName = opts.databaseFilename ?? gameConfig.databasePath;
 
             display.ResetWindow();