feat(bedrock): add guardrail support for agents

[krokoko]

Fixes #561

• Add guardrail support for agents
• Update CDK library version
• Update Projen version

Testing:

• Using the [https://github.com/aws-samples/generative-ai-cdk-constructs-samples/tree/main/samples/bedrock-agent](Bedrock Agent sample) , creating a guardrail and associating it with the agent

With agent.addGuardrail(guardrail); API:

Through constructor :

const agent = new bedrock.Agent(this, 'Agent', {
      foundationModel: bedrock.BedrockFoundationModel.ANTHROPIC_CLAUDE_INSTANT_V1_2,
      instruction: 'You are a helpful and friendly agent that answers questions about literature.',
      knowledgeBases: [kb],
      enableUserInput: true,
      shouldPrepareAgent:true,
      guardrailConfiguration: {
        guardrailId: guardrail.guardrailId,
        guardrailVersion: guardrail.guardrailVersion
      },
    });

Note: when providing guardrail config through the constructor, the customer has to provide correct permissions to the agent to use the guardrail. This is because we are currently not able to retrieve programmatically a guardrail based on id/version.

Use:

When asking a question, the trace shows correct use of guardrails:

When asking a question which falls under the guardrails boundaries, the correct fallback message is returned:

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.

[dineshSajwan]

LGTM