Add support for Amazon Bedrock

[davidmigloz]

Ref:

• https://aws.amazon.com/bedrock/
• https://python.langchain.com/v0.2/docs/integrations/chat/bedrock/

Dart client:

• Add support for Bedrock Runtime API agilord/aws_client#423
• https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters-anthropic-claude-text-completion.html

[ailabs-software]

Was just looking to see if we had this is the Dart port of LangChain.

Will prototype in Python, but having Bedrock client support for LangChain in dart would be handy.

[davidmigloz]

Hey @ailabs-software,

aws_client already added support for consuming the bedrock API, so it should be pretty straightforward (although it doesn't support streaming responses). If you're interested in implementing the integration, I can help you out.