chore: create use case interface

Author: AndreaGiulianelli

src/main/kotlin/usecase/UseCase.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2023. Smart Operating Block
+ *
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+package usecase
+
+/**
+ * This models a simple use case that return an object of type [X].
+ */
+interface UseCase<out X> {
+    /** Execute the use case returning an object of type [X]. */
+    fun execute(): X
+}