using Chain of Responsibility to refactor ConfigQueryRequestHandler and ConfigServletInner

[shiyiyue1102]

using Chain of Responsibility refactor ConfigQueryRequestHandler and ConfigServletInner, replacing current serval if-else statements.

Create ConfigQueryHandler and ConfigQueryHandlerChain,ConfigQueryHandlerChainBuilder. To exact BetaConfigQueryHandler-beta ,TagConfigQueryHandler-tag,FormalConfigQueryHandler-formal .

ConfigQueryHandlerChainBuilder builder with Handler of ordered name [ beta,tag,formal], if any handler matches this request,handler the request and return , delivery to next handler if not match.

ConfigQueryHandlerChainBuilder may design as a SPI interface ,for extensibility

[Bo-Qiu]

I wanna take it over, please assign to me, thx.