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