add required field in JSON schema, change exception thrown for one failure case

[sfbaker7]

Issue #, if available:

Description of changes: Adds a required field that is consistent with PutQueryDefinition API. This requires queryDef name, query string, and makes log group optional

Changes exception thrown when trying to update a non-existant resource from invalid request to not found as per CFN's contract testing requirements

Testing

Unit Tests

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  23.964 s
[INFO] Finished at: 2021-03-22T10:59:20-07:00
[INFO] ------------------------------------------------------------------------

Contract tests:

===================================================================== 13 passed, 3 skipped, 8 warnings in 895.06s (0:14:55) ======================================================================

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[markkuhn]

This PR has been open for more than a year. Can we close it?