trillium-client-v0.9.1

Added

• Conn::into_websocket now works over HTTP/3, in addition to the existing HTTP/2 and HTTP/1.1
  support. Hint the conn with Version::Http3 to upgrade a WebSocket over an HTTP/3 connection.
• ConnExt::upgrade and ConnExt::is_upgrade — mark a client conn for an upgrade. With upgrade
  marked, executing the conn transmits only the request headers and leaves the outbound direction
  open; the conn can then be converted into a trillium_http::Upgrade<Box<dyn Transport>> once
  response headers arrive (Upgrade::from(conn)).