Add flow and deviceType options to relay (#464)

* add flow and deviceType

for when authTitle is changed

* Update index.d.ts

---------

Co-authored-by: extremeheat <extreme@protonmail.ch>

index.d.ts

@@ -196,6 +196,9 @@ declare module 'bedrock-protocol' {
     // tokens to join the backend server. Cached after the first login.
     // If this is not specified, the client will be disconnected with a login prompt.
     onMsaCode?(data: ServerDeviceCodeResponse, client: Client): any
+    // prismarine-auth configuration
+    flow?: string,
+    deviceType?: string
   }
 
   export class Relay extends Server {

src/relay.js

@@ -186,6 +186,8 @@ class Relay extends Server {
   async openUpstreamConnection (ds, clientAddr) {
     const options = {
       authTitle: this.options.authTitle,
+      flow: this.options.flow,
+      deviceType: this.options.deviceType,
       offline: this.options.destination.offline ?? this.options.offline,
       username: this.options.offline ? ds.profile.name : ds.profile.xuid,
       version: this.options.version,