Refactor Benchmarking Workflow and Introduce New Data Models (#5264)

* New benchmark data models

* Update _benchmarkBaseUrl

* Remove ReportRequestBody

* Update benchmark service methods for proxy approach

* Add eval id to SkillNodeData

* Refactor runBenchmark Method for proxy approach

frontend/lib/models/skill_tree/skill_node_data.dart

@@ -9,6 +9,7 @@ class SkillNodeData {
   final int cutoff;
   final Ground ground;
   final Info info;
+  final String evalId;
 
   SkillNodeData({
     required this.name,
@@ -18,6 +19,7 @@ class SkillNodeData {
     required this.cutoff,
     required this.ground,
     required this.info,
+    required this.evalId,
   });
 
   factory SkillNodeData.fromJson(Map<String, dynamic> json) {
@@ -29,6 +31,7 @@ class SkillNodeData {
       cutoff: json['cutoff'] ?? 0,
       ground: Ground.fromJson(json['ground'] ?? {}),
       info: Info.fromJson(json['info'] ?? {}),
+      evalId: json['eval_id'] ?? "",
     );
   }
 }