chore(horaemeta&horaectl): refactor clusters/diagnose response body (a…

…pache#1475)

## Rationale
The response body returned by the clusters/diagnose HTTP API uses an
underscore style, which is inconsistent with the original style.

## Detailed Changes
Change it back to the original camelCase naming convention.

## Test Plan

ctl/operation/clusters.go

@@ -44,14 +44,14 @@ type ClusterResponse struct {
 }
 
 type DiagnoseShardStatus struct {
-	NodeName string `json:"node_name"`
+	NodeName string `json:"nodeName"`
 	Status   string `json:"status"`
 }
 
 type DiagnoseShardResponse struct {
 	// shardID -> nodeName
-	UnregisteredShards []uint32                       `json:"unregistered_shards"`
-	UnreadyShards      map[uint32]DiagnoseShardStatus `json:"unready_shards"`
+	UnregisteredShards []uint32                       `json:"unregisteredShards"`
+	UnreadyShards      map[uint32]DiagnoseShardStatus `json:"unreadyShards"`
 }
 
 func clusterUrl() string {

horaemeta/server/service/http/types.go

@@ -80,14 +80,14 @@ type API struct {
 }
 
 type DiagnoseShardStatus struct {
-	NodeName string `json:"node_name"`
+	NodeName string `json:"nodeName"`
 	Status   string `json:"status"`
 }
 
 type DiagnoseShardResult struct {
 	// shardID -> nodeName
-	UnregisteredShards []storage.ShardID                       `json:"unregistered_shards"`
-	UnreadyShards      map[storage.ShardID]DiagnoseShardStatus `json:"unready_shards"`
+	UnregisteredShards []storage.ShardID                       `json:"unregisteredShards"`
+	UnreadyShards      map[storage.ShardID]DiagnoseShardStatus `json:"unreadyShards"`
 }
 
 type QueryTableRequest struct {