Fix for the aws sdk CI test cases

[joeky888]

• Added a new get_nested_dict() helper that parses dot-notation query

• Fixed the CreateLaunchTemplate (and CreateLaunchTemplateVersion) request parser to use the new get_nested_dict() instead of get_scalar() for LaunchTemplateData

• Fixed the XML serializer for CreateSnapshot responses

I've also added a github action to test the aws sdk in the project-vera/aws-testcases repo. This PR is going to fix the CI test.

[joeky888]

Update from the Meeting:

1. In the sdk create_launch_template test, when boto3 sends a CreateLaunchTemplate request, it encodes it as form-encoded query parameters. There is no single LaunchTemplateData key — it's broken up into dot-notation sub-keys:

LaunchTemplateData.InstanceType=t2.micro
LaunchTemplateData.ImageId=ami-0abcdef1234567890

So get_scalar(md, "LaunchTemplateData") looks for a key literally named LaunchTemplateData, finds nothing, and returns None. The backend then sees LaunchTemplateData=None and rejects it as a missing required parameter.

get_nested_dict collects all keys starting with LaunchTemplateData. and assembles them into {'InstanceType': 't2.micro', 'ImageId': 'ami-...'}, which is the dict the backend actually expects.

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2. In the sdk create_snapshot test fails with InternalFailure: 'int' object is not iterable.

The snapshot response includes fullSnapshotSizeInBytes (an integer, e.g. 20) and progress (also a scalar like "0%"). The original serializer treated them as lists and tried to iterate over them:

for item in param_data:  # param_data is an int like 20 — can't iterate!
    xml_parts.append(f'<item>{esc(str(item))}</item>')

This crashes with 'int' object is not iterable. The fix changes them to simple scalar XML tags:

<fullSnapshotSizeInBytes>20</fullSnapshotSizeInBytes>
<progress>0%</progress>