Added Http request for available Tournaments

frontend_splatournament_manager/lib/models/tournament.dart

@@ -0,0 +1,25 @@
+class Tournament {
+  final int id;
+  final String name;
+  final String description;
+  final int maxTeamsAmount;
+  final int currentTeamAmount;
+
+  Tournament({
+    required this.id,
+    required this.name,
+    required this.description,
+    required this.maxTeamsAmount,
+    required this.currentTeamAmount,
+  });
+
+  factory Tournament.fromJson(dynamic json) {
+    return Tournament(
+      id: json['id'],
+      name: json['name'],
+      description: json['description'],
+      maxTeamsAmount: json['maxTeamsAmount'],
+      currentTeamAmount: json['currentTeamAmount'],
+    );
+  }
+}