support intercept specified command handler

[icodening]

Describe what this PR does / why we need it

support intercept specified command handler
example, users can extend support for authentication, suitable for "Zero Trust" network architecture

Does this pull request fix one issue?

Fixes #2578

Describe how you did it

wrap command handlers when based on conditions

Describe how to verify it

implement 'com.alibaba.csp.sentinel.command.CommandHandlerInterceptor' interface, and add file 'com.alibaba.csp.sentinel.command.CommandHandlerInterceptor' in META-INF/services dir

Special notes for reviews

example:

public class GetRulesCommandHandlerInterceptor implements CommandHandlerInterceptor {

    @Override
    public boolean shouldIntercept(String commandName) {
        // intercept the handler whose @CommandMapping name is "getRules"
        return "getRules".equals(commandName);
    }

    @Override
    public CommandResponse intercept(CommandRequest commandRequest, CommandRequestExecution commandRequestExecution) {
        // before handle
        CommandResponse response = commandRequestExecution.execute(commandRequest);
        // after handle
        return response;
    }
}

[sczyh30]

Any suggestions on this PR? @cdfive @brotherlu-xcq @alibaba/sentinel-committer

[brotherlu-xcq]

@icodening Nice work. but I think we need more discussion about your design. when one handler has more than one interceptors, I think we need execute all the interceptors if no one fail. and could you provide a flow chart to help us to know your idea?

[icodening]

@icodening Nice work. but I think we need more discussion about your design. when one handler has more than one interceptors, I think we need execute all the interceptors if no one fail. and could you provide a flow chart to help us to know your idea?

this is a simple flow chart

[brotherlu-xcq]

LGTM

[sczyh30]

LGTM

[sczyh30]

Thanks for contributing and look forward to more!