Add a User class with typical user properties and unit tests

Project/Sources/Classes/User.4dm

@@ -0,0 +1,11 @@
+property id : Text
+property name : Text
+property email : Text
+
+Class constructor($id : Text; $name : Text; $email : Text)
+    This.id := $id
+    This.name := $name
+    This.email := $email
+
+Function toString() : Text
+    return This.name + " <" + This.email + ">"

Project/Sources/Classes/UserTests.4dm

@@ -0,0 +1,10 @@
+var $user : cs.User
+
+// Test constructor
+$user:=cs.User.new("1"; "John Doe"; "[email protected]")
+ASSERT($user.id="1")
+ASSERT($user.name="John Doe")
+ASSERT($user.email="[email protected]")
+
+// Test toString method
+ASSERT($user.toString()="John Doe <[email protected]>")