[Umbrella] Preprocessor framework for AM and Client interactions with the RM

Currently on the NM, we have the AMRMProxy framework to intercept the AM <-> RM communication and enforce policies. This is used both by YARN federation (YARN-2915) as well as Distributed Scheduling (YARN-2877).

This JIRA proposes to introduce a similar framework on the the RM side, so that pluggable policies can be enforced on ApplicationMasterService centrally as well.

This would be similar in spirit to a Java Servlet Filter Chain. Where the order of the interceptors can declared externally.

Once possible usecase would be:
the OpportunisticContainerAllocatorAMService is implemented as a wrapper over the ApplicationMasterService. It would probably be better to implement it as an Interceptor.