feat: add ratelimit metrics in the ai-token-ratelimit plugin (#1918)

plugins/wasm-go/extensions/ai-token-ratelimit/config.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
 	"github.com/tidwall/gjson"
 	re "github.com/wasilibs/go-re2"
 	"github.com/zmap/go-iptree/iptree"
@@ -59,6 +60,7 @@ type ClusterKeyRateLimitConfig struct {
 	rejectedCode         uint32          // 当请求超过阈值被拒绝时,返回的HTTP状态码
 	rejectedMsg          string          // 当请求超过阈值被拒绝时,返回的响应体
 	redisClient          wrapper.RedisClient
+	counterMetrics       map[string]proxywasm.MetricCounter // Metrics
 }
 
 type LimitRuleItem struct {