Use gperf - not faster yet

src/commit_request.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "arena_allocator.hpp"
+#include "json_token_enum.hpp"
 #include <optional>
 #include <span>
 #include <stack>
@@ -82,6 +83,8 @@ public:
     ArenaAllocator arena;
 
     ParseState current_state = ParseState::Root;
+    JsonTokenType current_key_token;
+    // Only used if we need to accumulate the current key
     ArenaString current_key;
     ArenaString current_string;
     ArenaString current_number;