Initial WebSockets implementation

[RomanEmreis]

• Implemented HTTP/1 support
• Unstable HTTP/2 support

Example

use volga::App;
use tracing_subscriber::prelude::*;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    tracing_subscriber::registry()
        .with(tracing_subscriber::fmt::layer())
        .init();

    let mut app = App::new();

    app.map_message("/ws", |msg: String| async move {
        format!("received, {msg}", msg)
    });

    app.run().await
}