feat: move entity and usecase to root folder

entity/entity.go

@@ -0,0 +1,14 @@
+package entity
+
+import "github.com/google/uuid"
+
+type ID = uuid.UUID
+
+func NewID() ID {
+	return ID(uuid.New())
+}
+
+func StringToID(s string) (ID, error) {
+	id, err := uuid.Parse(s)
+	return ID(id), err
+}