added aws-guided codegen model

[ammokhov]

Issue #, if available:

Description of changes:

along with @rjlohan refactored codegen model to allow aws guided option. This option generates resource handlers (each handler has a special stub) and supporting files allowing developer to use functional paradigm.
refactored files:

• BaseHandlerStd - abstract class that has a handleRequst wrapper
• CreateHandler - has a sample create handler context pattern
• DeleteHandler - has a sample delete handler context pattern
• ReadHandler - has a sample read handler context pattern
• UpdateHandler - has a sample update handler context pattern
• ClientBuilder - has a sample sdkClient builder
• Translator - has sample api requests

Having progress chain pattern pre-generated for developers gives less function state control, less worry of exception handling, and more standardized approach for any future custom resource implementations.

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% cfn init
% Initializing new project
% What's the name of your resource type?% (Organization::Service::Resource)>> % One language plugin found, defaulting to java% Enter a package name (empty for default 'com.aa.aa.aa'):>>% Choose codegen model - 1 (default) or 2 (guided-aws):

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mvn verify builds successfully:

[INFO] All coverage checks have been met.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[aygold92]

please update the name of this PR

[aygold92]

can you please post the results of a sample code generation?

[aygold92]

please include a lengthy description of what testing you have done on this and include links to samples

[johnttompkins]

Overall looks good just some duplication in tests and a few open questions about some of the codegen changes below

[rjlohan]

Agree with most of the comments from @aygold92 we can make some more updates here.

[wbingli]

A few comments and also need a backfill the recent POJO fix.

[wbingli]

LGTM. But keep an eye on the POJO.java for a recent fix