feat: add optional server groups

Sources/Model/API/ServerGroup.swift

@@ -0,0 +1,11 @@
+import Foundation
+
+struct ServerGroup: Identifiable, Codable, Hashable, Equatable {
+    let id: UUID
+    var name: String
+
+    init(id: UUID = UUID(), name: String) {
+        self.id = id
+        self.name = name
+    }
+}