DEV: /channel -> /c chat route rename (#19782)

* DEV: Rnemae channel path to just c

Also swap the channel id and channel slug params to be consistent with core.

* linting

* channel_path

* params in wrong order

* Drop slugify helper and channel route without slug

* Request slug and route models through the channel model if possible

* Add client side redirection for backwards-compatibility

Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>

plugins/chat/assets/javascripts/discourse/models/chat-channel.js

@@ -5,6 +5,7 @@ import UserChatChannelMembership from "discourse/plugins/chat/discourse/models/u
 import { ajax } from "discourse/lib/ajax";
 import { escapeExpression } from "discourse/lib/utilities";
 import { tracked } from "@glimmer/tracking";
+import slugifyChannel from "discourse/plugins/chat/discourse/lib/slugify-channel";
 
 export const CHATABLE_TYPES = {
   directMessageChannel: "DirectMessage",
@@ -73,6 +74,14 @@ export default class ChatChannel extends RestModel {
     return escapeExpression(this.description);
   }
 
+  get slugifiedTitle() {
+    return this.slug || slugifyChannel(this);
+  }
+
+  get routeModels() {
+    return [this.slugifiedTitle, this.id];
+  }
+
   get isDirectMessageChannel() {
     return this.chatable_type === CHATABLE_TYPES.directMessageChannel;
   }