Add Bedrock Marketing Agent example

[lubao]

Issue #, if available:

Description of changes: The PR will add a use case example for bedrock marketing agent.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[lubao]

Thanks for reviewing the PR. Since the agent requires those sample datasets, do you have any suggestions on how to host the dataset properly?

[lubao]

remove db and image file to reduce the size.

[lubao]

Pass bandit and cfn_nag security check