support standard json format when update route from nameserver

[yuz10]

BUG REPORT

1. Please describe the issue you observed:

   • What did you do (The steps to reproduce)?
     update nameserver version to 4.9.4-snapshot (develop branch)
     and use go client to produce message

   • What did you expect to see?
     produce message success

   • What did you see instead?
     produce message fail
     because Let name server generate valid JSON response when process topic route queries rocketmq#4432 change route info to standard json such as:
     {"brokerDatas":[{"brokerAddrs":{"0":"127.0.0.1:10911"}}
     the old is:
     {"brokerDatas":[{"brokerAddrs":{0:"127.0.0.1:10911"}}

2. Please tell us about your environment:

   • What is your OS?

   • What is your client version?

   • What is your RocketMQ version?

3. Other information (e.g. detailed explanation, logs, related issues, suggestions on how to fix, etc):

FEATURE REQUEST

1. Please describe the feature you are requesting.

2. Provide any additional detail on your proposed use case for this feature.

3. Indicate the importance of this issue to you (blocker, must-have, should-have, nice-to-have). Are you currently using any workarounds to address this issue?

4. If there are some sub-tasks using -[] for each subtask and create a corresponding issue to map to the sub task:

   • sub-task1-issue-number: sub-task1 description here,
   • sub-task2-issue-number: sub-task2 description here,
   • ...

[duhenglucky]

@yuz10 It seems we'd better submit a PR to temporarily change it back to the previous way to ensure the compatibility of the old client. Compatibility is the first