feat/added bedrock streaming

[lloydhamilton]

What does this PR do?

Added streaming functionality for Bedrock API integration. Followed as closely as possible the coding styles written in openai_client.py and ollama_clienytpy.

• Added api call to bedrock .converse_stream endpoint when streaming is true.
• To enable streaming, set streaming = True is api_kwargs.

client = BedrockAPIClient(aws_profile_name="test_profile", aws_region_name="eu-west-1")
model_kwargs = {
    "modelId": "eu.anthropic.claude-3-5-sonnet-20240620-v1:0",
    "stream": True,
}

Since the stream parameter is not a parameter recognised by Bedrock, I had to add api_kwargs.pop("stream") when evaluating api_kwargs prior to bedrock API call.

Related issue:
#283

Add tests that extends the tests written in #289

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