Add Godot conversion extensions and update related code for integration

godot_game/Civilization.GodotIntegration/Utils/GodotConversionExtensions.cs

@@ -0,0 +1,13 @@
+using Civilization.Core;
+using Godot;
+
+namespace Civilization.GodotIntegration.Utils;
+
+public static class GodotConversionExtensions
+{
+    public static Vector2I ToGodot(this Vec2I v) => new(v.X, v.Y);
+    public static Vec2I ToCore(this Vector2I v) => new(v.X, v.Y);
+    
+    public static Color ToGodot(this ColorRGBA c) => new(c.R / 255f, c.G / 255f, c.B / 255f, c.A / 255f);
+    public static ColorRGBA ToCore(this Color c) => new((byte)(c.R * 255), (byte)(c.G * 255), (byte)(c.B * 255), (byte)(c.A * 255));
+}