[MCC-139802] Feature/create drd

So the diff is bigger than it should be based on the addition of a context block.  This PR merges the tests from ``` develop ``` into ``` moya_develop ```, adds an additional spec ``` 'responds appropriately to a drd create call specifying all permissible attributes' ``` and adds a create action to the drds controller.  I also threw in a couple of additional validations to match the descriptor doc in anticipation of making reality match it, and it match reality.  Error cases and their tests will be handled in a separate PR.

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14 examples, 0 failures, 5 pending
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