feat: add method call support and analyzeFull

- Add analyzeFull() to return Sema context with method table
- Improve method call desugaring: obj.method() → Type_method(obj)
- Search methodTable by method name when type inference fails
- Add methods.bux example demonstrating struct with extend blocks
- Use analyzeFull in cli.nim for proper method resolution

examples/methods.bux

@@ -0,0 +1,38 @@
+// Methods - Struct with methods using extend
+extern func Std_Io_PrintLine(s: String);
+extern func Std_Io_PrintInt(n: int);
+
+struct Rectangle {
+    width: int;
+    height: int;
+}
+
+extend Rectangle {
+    func Area(self: Rectangle) -> int {
+        return self.width * self.height;
+    }
+    
+    func Perimeter(self: Rectangle) -> int {
+        return 2 * (self.width + self.height);
+    }
+}
+
+func Main() -> int {
+    let rect: Rectangle = Rectangle { width: 10, height: 5 };
+    
+    Std_Io_PrintLine("Rectangle:");
+    Std_Io_PrintLine("Width = ");
+    Std_Io_PrintInt(rect.width);
+    Std_Io_PrintLine("");
+    Std_Io_PrintLine("Height = ");
+    Std_Io_PrintInt(rect.height);
+    Std_Io_PrintLine("");
+    Std_Io_PrintLine("Area = ");
+    Std_Io_PrintInt(rect.Area());
+    Std_Io_PrintLine("");
+    Std_Io_PrintLine("Perimeter = ");
+    Std_Io_PrintInt(rect.Perimeter());
+    Std_Io_PrintLine("");
+    
+    return 0;
+}