feat: add support for amazon bedrock knowledge base

[rkarthikr]

Closes #1514

📑 Description

Add support for Amazon Bedrock Knowledge Base as an AI backend provider for K8sGPT. This implementation allows users to leverage their existing knowledge bases in Amazon Bedrock to enhance Kubernetes cluster
analysis and troubleshooting capabilities. The feature includes necessary authentication methods, integration with the K8sGPT backend system, and comprehensive test coverage.

✅ Checks

• [ ✅ ] My pull request adheres to the code style of this project
• [ ✅ ] My code requires changes to the documentation
• [ ✅ ] I have updated the documentation as required
• [ ✅ ] All the tests have passed

[codecov]

Codecov Report

Attention: Patch coverage is 35.68075% with 137 lines in your changes missing coverage. Please review.

Project coverage is 42.90%. Comparing base (173e4dc) to head (689a061).
Report is 153 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/ai/amazonbedrockknowledgebase.go	35.96%	129 Missing and 1 partial ⚠️
cmd/auth/add.go	37.50%	5 Missing ⚠️
pkg/ai/iai.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1520      +/-   ##
==========================================
+ Coverage   34.76%   42.90%   +8.13%     
==========================================
  Files          94      108      +14     
  Lines        6342     7839    +1497     
==========================================
+ Hits         2205     3363    +1158     
- Misses       4046     4326     +280     
- Partials       91      150      +59     

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[AlexsJones]

Thanks for your PR, do you have any examples of this running?

[rkarthikr]

Thanks for your PR, do you have any examples of this running?