Allow support for headers within the AWS Bedrock SDK

[oof2win2]

Feature Description

All of the other provider adapters (OpenAI, Azure, Google, Mistral etc) support custom headers and base paths that can be used to provide additional information to the API, or change the API route. This is however missing in the AWS Bedrock SDK, and there is no alternative to set these options.

It would therefore make sense to make the Bedrock adapter in line with the other providers, so that base paths or headers can be changed.

Use Cases

Mainly observability tools.

Additional context

No response