AWS Route 53 InvalidBatchError customization does not work

[jbelkins]

Describe the bug

There is a customization in place to accommodate a difference between the published format of the InvalidBatchError operation error and the format actually returned by Route 53, i.e.:
https://github.com/awslabs/aws-sdk-swift/blob/main/codegen/smithy-aws-swift-codegen/src/main/kotlin/software/amazon/smithy/aws/swift/codegen/customization/route53/Route53InvalidBatchErrorIntegration.kt

However, this customization does not actually deserialize the data returned by Route 53 when an InvalidBatchError occurs.

Expected Behavior

The InvalidBatchError should be populated by error messages for the one or more errors that occur in a Route 53 batch update operation.

Current Behavior

The Message and Messages fields in an InvalidBatchError are both empty.

Reproduction Steps

Take the Route 53 integration test in this PR, and modify it to create an A record not in the hosted domain.
#1445

Run the test.

Possible Solution

No response

Additional Information/Context

No response

AWS SWIFT SDK version used

main

Compiler and Version used

Xcode 15.3

Operating System and version

macOS 14