chore: migrate user setting to api v1 package (#1855)

* chore: migrate to api v1 package

* chore: update

api/v1/memo.go

@@ -0,0 +1,25 @@
+package v1
+
+// Visibility is the type of a visibility.
+type Visibility string
+
+const (
+	// Public is the PUBLIC visibility.
+	Public Visibility = "PUBLIC"
+	// Protected is the PROTECTED visibility.
+	Protected Visibility = "PROTECTED"
+	// Private is the PRIVATE visibility.
+	Private Visibility = "PRIVATE"
+)
+
+func (v Visibility) String() string {
+	switch v {
+	case Public:
+		return "PUBLIC"
+	case Protected:
+		return "PROTECTED"
+	case Private:
+		return "PRIVATE"
+	}
+	return "PRIVATE"
+}