How to invoke a HTTP service

## Describe the feature/proposal

Include a section to invoke a HTTP service.

### Sample code

#### Cargo.toml

```rust
reqwest = "0.12.9"
dapr = "0.15.1"
tokio = "1.41.1"
```

After several optimizations, my `Cargo.toml` file is this way and it is running:

```rust
reqwest = { version = "0.12.9", default-features = false }
dapr = "0.15.1"
tokio = "1.41.1"
```

#### Rust code

This example uses:
- query parameter
- header value

```rust
tokio::runtime::Builder::new_current_thread()
.enable_all()
.build()
.unwrap()
.block_on(async {
let client_result = dapr::Client::::connect(format!("{}", ADDR)).await;
let method_to_call = format!("/{}", value);
match client_result {
Ok(mut client) => {
// Create a new HTTP client
let client = reqwest::Client::builder()
.timeout(Duration::from_secs(2)) // the value what you need
.build()
.unwrap();

// Post the method
// ADDR = "127.0.0.1"
// PORT =
let url = format!("{}:{}/{}", ADDR, PORT, method_to_call);
let req = client.post(url).header("dapr-app-id", "");

let response_result = req.send().await;
match response_result {
Ok(response) => {
let body_result = response.text().await;
match body_result {
Ok(body) => {
println!("Response: {:?}", body);
},
Err(e) => {
eprintln!("e1: {}", e);
}
}
},
Err(e) => {
eprintln!("e2: {}", e);
}
}
},
Err(e) => {
eprintln!("Dapr client error: {}", e);
}
}
});
```

## Release Note
RELEASE NOTE: **ADD** New example to invoke to a HTTP service in the Rust SDK.

Use the Cargo.toml dependency snippet and Rust code as source material; first locate the Rust SDK's existing documentation or example section where HTTP service invocation belongs. Add the example covering query parameters and a header value, then confirm the documentation presents the requested Rust usage clearly.

Written by the indexing model from the issue text.