inboundNode should be split according to resource type

[ansiz]

Issue Description

Type: feature request

希望能够将inboundNode更细粒度的拆分

Describe what feature you want

目前sentinel中所有的流量类型的数据都会计入inboundNode中，但实际上业务上可能需要更为详细的区分，以Concurrency为例，rpc、消息、网关api和http请求混合在一起时，该指标失去了原本的意义。如果能够拆分成totalRPCInbound、totalHTTPInbound、totalMQInbound，业务才能根据更加具体的统计信息决策后续的限流逻辑

[luckyxiaoqiang]

Please assign this to me. @louyuting

[louyuting]

Nice