Move JavaResourcePackConverter to its own cs proj

JavaResourcePackConverter/Java/SingleVersion.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace JavaResourcePackConverter
+{
+    class SingleVersion(Version version) : IMinecraftJavaVersion
+    {
+        private readonly Version _version = version;
+
+        public SingleVersion(string version) : this(new Version(version)) { }
+
+        public bool Equals(Version other) => _version.Equals(other);
+
+        public string ToString(string _) => _version.ToString();
+    }
+}