[dev] reconnect socket after bad protocol message

[EverlastingBugstopper]

fixes #1241

after a while, the preview service disconnects the websocket, even if you're being a good citizen and sending keep alive heartbeat messages every now and then. for shame! after merging this if your dev session gets disconnected from the websocket we'll issue a reconnect. :) :) :)

[EverlastingBugstopper]

getting a pretty opaque compiler error that i'm not sure how to resolve..

error: future cannot be sent between threads safely
   --> src/commands/dev/socket.rs:59:23
    |
59  |         let printer = tokio::spawn(print_ws_messages(Arc::clone(&passable_read)))
    |                       ^^^^^^^^^^^^ future returned by `print_ws_messages` is not `Send`
    | 
   ::: /Users/averyharnish/.cargo/registry/src/github.aaakk.us.kg-1ecc6299db9ec823/tokio-0.2.20/src/task/spawn.rs:127:21
    |
127 |         T: Future + Send + 'static,
    |                     ---- required by this bound in `tokio::task::spawn::spawn`
    |
    = help: within `impl core::future::future::Future`, the trait `std::marker::Send` is not implemented for `std::sync::MutexGuard<'_, futures_util::stream::stream::split::SplitStream<tokio_tungstenite::WebSocketStream<tokio_tungstenite::stream::Stream<tokio::net::tcp::stream::TcpStream, tokio_tls::TlsStream<tokio::net::tcp::stream::TcpStream>>>>>`
note: future is not `Send` as this value is used across an await
   --> src/commands/dev/socket.rs:77:31
    |
76  |     let mut read = read.lock().unwrap();
    |         -------- has type `std::sync::MutexGuard<'_, futures_util::stream::stream::split::SplitStream<tokio_tungstenite::WebSocketStream<tokio_tungstenite::stream::Stream<tokio::net::tcp::stream::TcpStream, tokio_tls::TlsStream<tokio::net::tcp::stream::TcpStream>>>>>` which is not `Send`
77  |     while let Some(message) = read.next().await {
    |                               ^^^^^^^^^^^^^^^^^ await occurs here, with `mut read` maybe used later
...
94  | }
    | - `mut read` is later dropped here

i want an async fn that i can spawn and then try_join

and if an error occurs in either of the futures i've spawned (keep_alive messages and printing incoming socket messages) i want to kill the futures i've spawned and start my listen fn over from the beginning

[EverlastingBugstopper]

@ObsidianMinor thanks so much for the review 😄