[FLINK-36359][Connectors/DynamoDB] IT Case for DDB Streams connector

[karanmakhija867]

Purpose of the change

Set up ITCase for DDB Streams connector using localstack

Verifying this change

Please make sure both new and modified tests in this PR follows the conventions defined in our code quality guide: https://flink.apache.org/contributing/code-style-and-quality-common.html#testing

This change added tests and can be verified as follows:

• Added integration test for DDB Streams connector

Significant changes

(Please check any boxes [x] if the answer is "yes". You can first publish the PR and check them afterwards, for convenience.)

• Dependencies have been added or upgraded
• Public API has been changed (Public API is any class annotated with @Public(Evolving))
• Serializers have been changed
• New feature has been introduced
  • If yes, how is this documented? (not applicable / docs / JavaDocs / not documented)

[boring-cyborg]

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