Bedrock managed prompts examples

[AWSChris]

This pull request adds Python examples for creating, invoking, and deleting Amazon Bedrock managed prompts.

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[brmur]

@AWSChris There are some errors in the GH actions for this PR. See metadata errors ( https://github.com/awsdocs/aws-doc-sdk-examples/actions/runs/14671910495/job/41266957670?pr=7418 ) and a Yaml formatting error (https://github.com/awsdocs/aws-doc-sdk-examples/actions/runs/14671910485/job/41266957366?pr=7418).

[rlhagerm]

Just a few comments/questions, otherwise looks really good.

[rlhagerm]

@brmur and @AWSChris , for the InvokePrompt example, I tried several ways to correct the metadata but finally realized it's an action on another service, and so I removed that part of the metadata to pass the validators. If you want to try to add it to the other service, that will probably work.