feat: add openim images config path

Signed-off-by: Xinwei Xiong(cubxxw) <3293172751nss@gmail.com>

pkg/common/metrics/gin_api.go

@@ -0,0 +1,16 @@
+package prom_metrics
+
+import ginProm "github.com/openimsdk/open-im-server/v3/pkg/common/ginprom"
+
+/*
+labels := prometheus.Labels{"label_one": "any", "label_two": "value"}
+ApiCustomCnt.MetricCollector.(*prometheus.CounterVec).With(labels).Inc()
+*/
+var (
+	ApiCustomCnt = &ginProm.Metric{
+		Name:        "custom_total",
+		Description: "Custom counter events.",
+		Type:        "counter_vec",
+		Args:        []string{"label_one", "label_two"},
+	}
+)