[Enhancement]: Add bedrock-runtime-agent examples for Rust

[mattiapitossi]

Background story

Hi there,

I would like to contribute in adding some Rust examples for AWS service Bedrock Agent Runtime. I'm linking the first PR on this ticket.

What does this example accomplish?

Demonstrate how to use invoke agent command in Rust (can be extended also with invoke-flow)

Which AWS service(s)?

Bedrock Agent Runtime

Which AWS SDKs or tools?

• [ ] All languages
• [ ] .NET
• [ ] C++
• [ ] Go (v2)
• [ ] Java
• [ ] Java (v2)
• [ ] JavaScript
• [ ] JavaScript (v3)
• [ ] Kotlin
• [ ] PHP
• [ ] Python
• [ ] Ruby
• [x] Rust
• [ ] Swift
• [ ] Not applicable

Are there existing code examples to leverage?

No response

Do you have any reference code?