genai: Created Package & implemented LLM Config, Manager & Request

packages/genai/lib/llm_request.dart

@@ -0,0 +1,13 @@
+class LLMRequestDetails {
+  String endpoint;
+  Map<String, String> headers;
+  String method;
+  Map<String, dynamic> body;
+
+  LLMRequestDetails({
+    required this.endpoint,
+    required this.headers,
+    required this.method,
+    required this.body,
+  });
+}