v2.1.0-alpha.5

Add support for ignored performance/metrics parameters

Updated FakeDynamoDBInterface to accept (but ignore) the following
parameters that are purely informational or related to AWS optimization:

- ReturnConsumedCapacity: Added to get, put, delete, batchWrite,
  transactionWrite, queryOnePage, queryAllPages, scanOnePage, scanAllPages
  - Returns information about consumed capacity units
  - No meaning in an in-memory implementation

- ReturnItemCollectionMetrics: Added to put, delete, batchWrite,
  transactionWrite
  - Returns statistics about item collection sizes
  - No meaning in an in-memory implementation

- ClientRequestToken: Added to transactionWrite
  - Used for making operations idempotent
  - In-memory operations are already atomic/instant

These parameters are now accepted to maintain compatibility with real
DynamoDB operations but are not processed as they have no meaning in
a fake in-memory implementation.

Updated unit tests to verify that these parameters are accepted for all
applicable operations instead of throwing errors.