Issue #, if available:
WIP for protocol tests for this SDK
Description of changes:

1. Refactor python wrappers over code generators present on this SDK by extracting the logic into separate submodules for re-use and read-ability (I hope so).
2. Add "protocol test clients" (sample clients for a fictional services used for test purposes) generation to the SDK.
   These clients should look, act, and behave just like any regular generated SDK client but are used for SDK testing only.

Tested by generating all and observing that no unexpected difference is generated.
The only difference is

$ python3 tools/scripts/run_code_generation.py --generate_protocol_tests
...
$ ls -a generated/protocol-tests/test-clients
aws-cpp-sdk-ec2-protocol
aws-cpp-sdk-json-protocol
aws-cpp-sdk-json-rpc-10
aws-cpp-sdk-query-protocol
aws-cpp-sdk-rest-json-protocol
aws-cpp-sdk-rest-xml-protocol
aws-cpp-sdk-rest-xml-protocol-namespace

Check all that applies:

• Did a review by yourself.
• Added proper tests to cover this PR. (If tests are not applicable, explain.)
• Checked if this PR is a breaking (APIs have been changed) change.
• Checked if this PR will not introduce cross-platform inconsistent behavior.
• Checked if this PR would require a ReadMe/Wiki update.

Check which platforms you have built SDK on to verify the correctness of this PR.

• Linux
• Windows
• Android
• MacOS
• IOS
• Other Platforms

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