Feat: Add AWS Bedrock Agents as a new provider

[chezsmithy]

Description

This could resolve: https://github.com/continuedev/continue/issues/2874

This feature is someone experimental, and is one approach to incorporating AWS Bedrock agents as a dedicated provider. The solution allows defining one to many AWS bedrock agents as a dedicated provider and the user can easily toggle between them to perform dedicated tasks.

New agents can easily be added to the configuration as a provider quickly and easily.

For example:

    {
      "title": "Gherkin Agent",
      "provider": "bedrockagent",
      "model": "anthropic.claude-3-5-sonnet-20241022-v2:0",
      "region": "us-west-2",
      "profile": "bedrock",
      "agentId": "<AgentID>",
      "agentAliasId": "<AgentAliasId>"
    },

Limitations and questions:

• I've not found an easy way to share the taskid with the provider to prime the sessionId for AWS Bedrock Agent Session Memory. I'd love some good ideas how to make this work. I've also added this as a question on the contributors channel on discord if you would like to help me out over there.
• Is this useful, vs a MCP tools approach which activates the agent on the fly? There may be value in having direct conversations with a specific agent which might also include supervisor tooling. For example, bringing a more educational but less code focused tool into the developer experience instead of forcing the developer to another UI to use those experiences.
• The model is required in the configuration and must be matched to the model used by AWS bedrock. This is a limitation because the prompt formatting and interpretation on the client side is highly dependent on the model and that's not easily exposed from AWS from what I can see.

Other Considerations:

• This PR is updating AWS libraries to be at a single consistent version to support plugging in the aws bedrock agents library. I've tested, but I'm always overly causious of these impacts.

Checklist

• [X] The relevant docs, if any, have been updated or created
• [X] The relevant tests, if any, have been updated or created

Screenshots

[ For visual changes, include screenshots. ]

Testing instructions

This new provider shares AWS profile configuration with other AWS models like bedrock and bedrock-import.

Once you have configured a new agent as a provider you can choose the agent from the provider drop down and have a dedicated discussion with the agent in real time.