[SCB-311] Support Record Custom Metrics in Java Chassis Itself

[zhengyangyong]

Signed-off-by: zhengyangyong yangyong.zheng@huawei.com

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[coveralls]

Coverage decreased (-0.1%) to 87.3% when pulling 51cfddd on zhengyangyong:SCB-311 into 8e84b30 on apache:master.

[wujimin]

current custom metric mechanism maybe not good, i will do some test first, and then confirm this PR.

[WillemJiang]

It looks like a refactoring that reuses the customer metric for the other module.

What about the old implementation, I don't see the move changes in the PR.
@zhengyangyong do you have any plan to remove old implementation?

[zhengyangyong]

No , I only extend Events let developers can raise 'Record Custom Metrics Event' same as Java Chassis raise 'Invocation Event' mechanism,so no any move changes in the PR.
Becuase metrics is a Optional module and Java Chassis can't direct autowire CounterService,GaugeService and WindowCounterService in metrics-core.

[zhengyangyong]

I don't think we need remove old implementation,direct use CounterService,GaugeService and WindowCounterService record custom metrics may more efficient and friendly than raise event,this mechanism is only recommend for 'Java Chassis Developer'

[wujimin]

chassis are metrics's customers
chassis's customers and chassis should use the same mechanism.